Make cypclass wrappers mirror single inheritance of underlying cypclass

Cython/Compiler/CypclassWrapper.py

@@ -102,6 +102,7 @@ class CypclassWrapperInjection(VisitorTransform):
     def __call__(self, root):
         self.cypclass_wrappers_stack = []
         self.nesting_stack = []
+        self.module_scope = root.scope
         return super(CypclassWrapperInjection, self).__call__(root)
 
     def visit_Node(self, node):
@@ -154,17 +155,45 @@ 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)
 
         from .ExprNodes import TupleNode
-        cclass_bases = TupleNode(node.pos, args=[])
+        bases_args = []
+        if node.base_classes:
+            first_base = node.base_classes[0]
+            if isinstance(first_base, Nodes.CSimpleBaseTypeNode) and first_base.templates is None:
+                first_base_name = first_base.name
+                builtin_entry = self.module_scope.lookup(first_base_name)
+                if builtin_entry is not None:
+                    return
+                wrapped_first_base = Nodes.CSimpleBaseTypeNode(
+                    first_base.pos,
+                    name = "%s_cyp_wrapper" % first_base_name,
+                    module_path = [],
+                    is_basic_c_type = first_base.is_basic_c_type,
+                    signed = first_base.signed,
+                    complex = first_base.complex,
+                    longness = first_base.longness,
+                    is_self_arg = first_base.is_self_arg,
+                    templates = None
+                )
+                bases_args.append(wrapped_first_base)
+
+        cclass_bases = TupleNode(node.pos, args=bases_args)
 
         # the underlying cyobject must come first thing after PyObject_HEAD in the memory layout
         # long term, only the base class will declare the underlying attribute
+
+        stats = []
+        if not bases_args:
             underlying_cyobject = self.synthesize_underlying_cyobject_attribute(node)
-        stats = [underlying_cyobject]
+            stats.append(underlying_cyobject)
         cclass_body = Nodes.StatListNode(pos=node.pos, stats=stats)
+
         cclass_doc = EncodedString("Python Object wrapper for underlying cypclass %s" % node.name)
 
         wrapper = Nodes.CypclassWrapperDefNode(
@@ -182,7 +211,7 @@ class CypclassWrapperInjection(VisitorTransform):
             in_pxd = node.in_pxd,
             doc = cclass_doc,
             body = cclass_body,
-            wrapped_cypclass = node
+            wrapped_cypclass = node,
         )
 
         return wrapper
@@ -717,9 +746,10 @@ def generate_cyp_class_wrapper_definition(type, wrapper_entry, constructor_entry
     # initialise PyObject fields
     if is_new_return_type and type.wrapper_type:
         objstruct_cname = type.wrapper_type.objstruct_cname
+        cclass_wrapper_base = type.wrapped_base_type.wrapper_type
         code.putln("if(self) {")
         code.putln("%s * wrapper = new %s();" % (objstruct_cname, objstruct_cname))
-        code.putln("wrapper->nogil_cyobject = self;")
+        code.putln("((%s *)wrapper)->nogil_cyobject = self;" % cclass_wrapper_base.objstruct_cname)
         code.putln("PyObject * wrapper_as_py = (PyObject *) wrapper;")
         code.putln("wrapper_as_py->ob_refcnt = 0;")
         code.putln("wrapper_as_py->ob_type = %s;" % type.wrapper_type.typeptr_cname)

Cython/Compiler/Nodes.py

@@ -5441,7 +5441,15 @@ class CypclassWrapperDefNode(CClassDefNode):
 
         # > access the method of the underlying cyobject from the self argument of the wrapper method
         underlying_obj = ExprNodes.AttributeNode(cfunc_method.pos, obj=self_obj, attribute=underlying_name)
-        cfunc = ExprNodes.AttributeNode(cfunc_method.pos, obj=underlying_obj, attribute=cfunc_name)
+        empty_declarator = CNameDeclaratorNode(cfunc_method.pos, name="", cname=None)
+        cast_underlying_obj = ExprNodes.TypecastNode(
+            cfunc_method.pos,
+            type = self.wrapped_cypclass.entry.type,
+            operand = underlying_obj,
+            typecheck = False
+        )
+
+        cfunc = ExprNodes.AttributeNode(cfunc_method.pos, obj=cast_underlying_obj, attribute=cfunc_name)
 
         # > call to the underlying method
         c_call = ExprNodes.SimpleCallNode(

Cython/Compiler/PyrexTypes.py

@@ -3961,16 +3961,31 @@ class CypClassType(CppClassType):
     #  lock_mode          string (tri-state: "nolock"/"checklock"/"autolock")
     #  _mro               [CppClassType] or None       the Method Resolution Order of this cypclass according to Python
     #  wrapper_type       PyExtensionType or None      the type of the cclass wrapper
+    #  wrapped_base_type     CypClassType or None         the type of the oldest wrapped cypclass base
 
     is_cyp_class = 1
     to_py_function = None
 
     def __init__(self, name, scope, cname, base_classes, templates=None, template_type=None, nogil=0, lock_mode=None, activable=False):
         CppClassType.__init__(self, name, scope, cname, base_classes, templates, template_type, nogil)
+        if base_classes:
+            self.find_wrapped_base_type(base_classes)
         self.lock_mode = lock_mode if lock_mode else "autolock"
         self.activable = activable
         self._mro = None
-        self.wrapper_type = None # set during
+        self.wrapper_type = None
+        self.wrapped_base_type = None
+
+    def find_wrapped_base_type(self, base_classes):
+        first_wrapped_cypclass_base = None
+        for base_type in base_classes:
+            if base_type.is_cyp_class and base_type.wrapper_type:
+                first_wrapped_cypclass_base = base_type
+                break
+        if first_wrapped_cypclass_base:
+            self.wrapped_base_type = first_wrapped_cypclass_base.wrapped_base_type
+        else:
+            self.wrapped_base_type = self
 
     # Return the MRO for this cypclass
     # Compute all the mro needed when a previous computation is not available
@@ -4005,7 +4020,7 @@ class CypClassType(CppClassType):
     def create_from_py_utility_code(self, env):
         if not self.wrapper_type:
             return False
-        wrapper_objstruct = self.wrapper_type.objstruct_cname
+        wrapper_objstruct = self.wrapped_base_type.wrapper_type.objstruct_cname
         underlying_type_name = self.cname
         self.from_py_function = "__Pyx_PyObject_AsCyObject<%s, %s>" % (wrapper_objstruct, underlying_type_name)
         return True

Cython/Compiler/Symtab.py

@@ -735,6 +735,8 @@ class Scope(object):
                     entry.already_declared_here()
                 else:
                     entry.type.base_classes = base_classes
+                    if cypclass:
+                        entry.type.find_wrapped_base_type(base_classes)
             if templates or entry.type.templates:
                 if templates != entry.type.templates:
                     error(pos, "Template parameters do not match previous declaration")