/// <summary> /// Metatype __call__ implementation. This is needed to ensure correct /// initialization (__init__ support), because the tp_call we inherit /// from PyType_Type won't call __init__ for metatypes it doesn't know. /// </summary> public static IntPtr tp_call(IntPtr tp, IntPtr args, IntPtr kw) { IntPtr func = Marshal.ReadIntPtr(tp, TypeOffset.tp_new); if (func == IntPtr.Zero) { return(Exceptions.RaiseTypeError("invalid object")); } IntPtr obj = NativeCall.Call_3(func, tp, args, kw); if (obj == IntPtr.Zero) { return(IntPtr.Zero); } var init = Runtime.PyObject_GetAttrString(obj, "__init__"); Runtime.PyErr_Clear(); if (init != IntPtr.Zero) { IntPtr result = Runtime.PyObject_Call(init, args, kw); Runtime.XDecref(init); if (result == IntPtr.Zero) { Runtime.XDecref(obj); return(IntPtr.Zero); } Runtime.XDecref(result); } return(obj); }
/// <summary> /// Metatype __new__ implementation. This is called to create a new /// class / type when a reflected class is subclassed. /// </summary> public static IntPtr tp_new(IntPtr tp, IntPtr args, IntPtr kw) { var len = Runtime.PyTuple_Size(args); if (len < 3) { return(Exceptions.RaiseTypeError("invalid argument list")); } IntPtr name = Runtime.PyTuple_GetItem(args, 0); IntPtr bases = Runtime.PyTuple_GetItem(args, 1); IntPtr dict = Runtime.PyTuple_GetItem(args, 2); // We do not support multiple inheritance, so the bases argument // should be a 1-item tuple containing the type we are subtyping. // That type must itself have a managed implementation. We check // that by making sure its metatype is the CLR metatype. if (Runtime.PyTuple_Size(bases) != 1) { return(Exceptions.RaiseTypeError("cannot use multiple inheritance with managed classes")); } IntPtr base_type = Runtime.PyTuple_GetItem(bases, 0); IntPtr mt = Runtime.PyObject_TYPE(base_type); if (!(mt == PyCLRMetaType || mt == Runtime.PyTypeType)) { return(Exceptions.RaiseTypeError("invalid metatype")); } // Ensure that the reflected type is appropriate for subclassing, // disallowing subclassing of delegates, enums and array types. var cb = GetManagedObject(base_type) as ClassBase; if (cb != null) { if (!cb.CanSubclass()) { return(Exceptions.RaiseTypeError("delegates, enums and array types cannot be subclassed")); } } IntPtr slots = Runtime.PyDict_GetItemString(dict, "__slots__"); if (slots != IntPtr.Zero) { return(Exceptions.RaiseTypeError("subclasses of managed classes do not support __slots__")); } // If __assembly__ or __namespace__ are in the class dictionary then create // a managed sub type. // This creates a new managed type that can be used from .net to call back // into python. if (IntPtr.Zero != dict) { Runtime.XIncref(dict); using (var clsDict = new PyDict(dict)) { if (clsDict.HasKey("__assembly__") || clsDict.HasKey("__namespace__")) { return(TypeManager.CreateSubType(name, base_type, dict)); } } } // otherwise just create a basic type without reflecting back into the managed side. IntPtr func = Marshal.ReadIntPtr(Runtime.PyTypeType, TypeOffset.tp_new); IntPtr type = NativeCall.Call_3(func, tp, args, kw); if (type == IntPtr.Zero) { return(IntPtr.Zero); } int flags = TypeFlags.Default; flags |= TypeFlags.Managed; flags |= TypeFlags.HeapType; flags |= TypeFlags.BaseType; flags |= TypeFlags.Subclass; flags |= TypeFlags.HaveGC; Util.WriteCLong(type, TypeOffset.tp_flags, flags); TypeManager.CopySlot(base_type, type, TypeOffset.tp_dealloc); // Hmm - the standard subtype_traverse, clear look at ob_size to // do things, so to allow gc to work correctly we need to move // our hidden handle out of ob_size. Then, in theory we can // comment this out and still not crash. TypeManager.CopySlot(base_type, type, TypeOffset.tp_traverse); TypeManager.CopySlot(base_type, type, TypeOffset.tp_clear); // for now, move up hidden handle... IntPtr gc = Marshal.ReadIntPtr(base_type, TypeOffset.magic()); Marshal.WriteIntPtr(type, TypeOffset.magic(), gc); return(type); }