feat: Restrict __slots__=() for subclasses of tvm_ffi.Object by default

docs/conf.py

@@ -282,7 +282,9 @@ def _link_inherited_members(app, what, name, obj, options, lines) -> None:  # no
     # If it comes from builtins we already hide it; no link needed
     if base in _py_native_classes or getattr(base, "__module__", "") == "builtins":
         return
-    owner_fq = f"{base.__module__}.{base.__qualname__}".replace("tvm_ffi.core.", "tvm_ffi.")
+    owner_fq = f"{base.__module__}.{base.__qualname__}".replace(
+        "tvm_ffi.core.", "tvm_ffi."
+    ).replace(".CObject", ".Object")
     role = "attr" if what in {"attribute", "property"} else "meth"
     lines.clear()
     lines.append(
@@ -329,6 +331,9 @@ def _import_cls(cls_name: str) -> type | None:
     "__ffi_init__",
     "__from_extern_c__",
     "__from_mlir_packed_safe_call__",
+    "_move",
+    "__move_handle_from__",
+    "__init_handle_by_constructor__",
 }
 # If a member method comes from one of these native types, hide it in the docs
 _py_native_classes: tuple[type, ...] = (

python/tvm_ffi/core.pyi

@@ -32,7 +32,7 @@ _TRACEBACK_TO_BACKTRACE_STR: Callable[[types.TracebackType | None], str] | None
 # DLPack protocol version (defined in tensor.pxi)
 __dlpack_version__: tuple[int, int]
 
-class Object:
+class CObject:
     def __ctypes_handle__(self) -> Any: ...
     def __chandle__(self) -> int: ...
     def __reduce__(self) -> Any: ...
@@ -46,7 +46,9 @@ class Object:
     def __ffi_init__(self, *args: Any) -> None: ...
     def same_as(self, other: Any) -> bool: ...
     def _move(self) -> ObjectRValueRef: ...
-    def __move_handle_from__(self, other: Object) -> None: ...
+    def __move_handle_from__(self, other: CObject) -> None: ...
+
+class Object(CObject): ...
 
 class ObjectConvertible:
     def asobject(self) -> Object: ...

python/tvm_ffi/cython/base.pxi

@@ -392,6 +392,7 @@ cdef extern from "tvm_ffi_python_helpers.h":
 
 
 cdef class ByteArrayArg:
+    __slots__ = ()
     cdef TVMFFIByteArray cdata
     cdef object py_data
 

python/tvm_ffi/cython/device.pxi

@@ -91,6 +91,7 @@ cdef class Device:
         assert str(dev) == "cuda:0"
 
     """
+    __slots__ = ()
     cdef DLDevice cdevice
 
     _DEVICE_TYPE_TO_NAME = {

python/tvm_ffi/cython/dtype.pxi

@@ -79,6 +79,7 @@ cdef class DataType:
         assert str(d) == "int32"
 
     """
+    __slots__ = ()
     cdef DLDataType cdtype
 
     def __init__(self, dtype_str: str) -> None:

python/tvm_ffi/cython/error.pxi

@@ -27,7 +27,7 @@ _WITH_APPEND_BACKTRACE: Optional[Callable[[BaseException, str], BaseException]]
 _TRACEBACK_TO_BACKTRACE_STR: Optional[Callable[[types.TracebackType | None], str]] = None
 
 
-cdef class Error(Object):
+cdef class Error(CObject):
     """Base class for FFI errors.
 
     An :class:`Error` is a lightweight wrapper around a concrete Python
@@ -43,6 +43,7 @@ cdef class Error(Object):
     Do not directly raise this object. Instead, use :py:meth:`py_error`
     to convert it to a Python exception and raise that.
     """
+    __slots__ = ()
 
     def __init__(self, kind: str, message: str, backtrace: str):
         """Construct an error wrapper.
@@ -66,7 +67,7 @@ cdef class Error(Object):
         )
         if ret != 0:
             raise MemoryError("Failed to create error object")
-        (<Object>self).chandle = out
+        (<CObject>self).chandle = out
 
     def update_backtrace(self, backtrace: str) -> None:
         """Replace the stored backtrace string with ``backtrace``.
@@ -107,7 +108,7 @@ cdef class Error(Object):
 cdef inline Error move_from_last_error():
     # raise last error
     error = Error.__new__(Error)
-    TVMFFIErrorMoveFromRaised(&(<Object>error).chandle)
+    TVMFFIErrorMoveFromRaised(&(<CObject>error).chandle)
     return error
 
 

python/tvm_ffi/cython/function.pxi

@@ -131,7 +131,7 @@ cdef int TVMFFIPyArgSetterTensor_(
     TVMFFIPyArgSetter* handle, TVMFFIPyCallContext* ctx,
     PyObject* arg, TVMFFIAny* out
 ) except -1:
-    if (<Object>arg).chandle != NULL:
+    if (<CObject>arg).chandle != NULL:
         out.type_index = kTVMFFITensor
         out.v_ptr = (<Tensor>arg).chandle
     else:
@@ -144,8 +144,8 @@ cdef int TVMFFIPyArgSetterObject_(
     TVMFFIPyArgSetter* handle, TVMFFIPyCallContext* ctx,
     PyObject* arg, TVMFFIAny* out
 ) except -1:
-    out.type_index = TVMFFIObjectGetTypeIndex((<Object>arg).chandle)
-    out.v_ptr = (<Object>arg).chandle
+    out.type_index = TVMFFIObjectGetTypeIndex((<CObject>arg).chandle)
+    out.v_ptr = (<CObject>arg).chandle
     return 0
 
 
@@ -312,7 +312,7 @@ cdef int TVMFFIPyArgSetterFFIObjectProtocol_(
     """Setter for objects that implement the `__tvm_ffi_object__` protocol."""
     cdef object arg = <object>py_arg
     cdef TVMFFIObjectHandle temp_chandle
-    cdef Object obj = arg.__tvm_ffi_object__()
+    cdef CObject obj = arg.__tvm_ffi_object__()
     cdef long ref_count = Py_REFCNT(obj)
     temp_chandle = obj.chandle
     out.type_index = TVMFFIObjectGetTypeIndex(temp_chandle)
@@ -418,8 +418,8 @@ cdef int TVMFFIPyArgSetterPyNativeObjectStr_(
     # need to check if the arg is a large string returned from ffi
     if arg._tvm_ffi_cached_object is not None:
         arg = arg._tvm_ffi_cached_object
-        out.type_index = TVMFFIObjectGetTypeIndex((<Object>arg).chandle)
-        out.v_ptr = (<Object>arg).chandle
+        out.type_index = TVMFFIObjectGetTypeIndex((<CObject>arg).chandle)
+        out.v_ptr = (<CObject>arg).chandle
         return 0
     return TVMFFIPyArgSetterStr_(handle, ctx, py_arg, out)
 
@@ -457,8 +457,8 @@ cdef int TVMFFIPyArgSetterPyNativeObjectBytes_(
     # need to check if the arg is a large bytes returned from ffi
     if arg._tvm_ffi_cached_object is not None:
         arg = arg._tvm_ffi_cached_object
-        out.type_index = TVMFFIObjectGetTypeIndex((<Object>arg).chandle)
-        out.v_ptr = (<Object>arg).chandle
+        out.type_index = TVMFFIObjectGetTypeIndex((<CObject>arg).chandle)
+        out.v_ptr = (<CObject>arg).chandle
         return 0
     return TVMFFIPyArgSetterBytes_(handle, ctx, py_arg, out)
 
@@ -473,8 +473,8 @@ cdef int TVMFFIPyArgSetterPyNativeObjectGeneral_(
         raise ValueError(f"_tvm_ffi_cached_object is None for {type(arg)}")
     assert arg._tvm_ffi_cached_object is not None
     arg = arg._tvm_ffi_cached_object
-    out.type_index = TVMFFIObjectGetTypeIndex((<Object>arg).chandle)
-    out.v_ptr = (<Object>arg).chandle
+    out.type_index = TVMFFIObjectGetTypeIndex((<CObject>arg).chandle)
+    out.v_ptr = (<CObject>arg).chandle
     return 0
 
 
@@ -507,7 +507,7 @@ cdef int TVMFFIPyArgSetterObjectRValueRef_(
     """Setter for ObjectRValueRef"""
     cdef object arg = <object>py_arg
     out.type_index = kTVMFFIObjectRValueRef
-    out.v_ptr = &((<Object>(arg.obj)).chandle)
+    out.v_ptr = &((<CObject>(arg.obj)).chandle)
     return 0
 
 
@@ -532,8 +532,8 @@ cdef int TVMFFIPyArgSetterException_(
     """Setter for Exception"""
     cdef object arg = <object>py_arg
     arg = _convert_to_ffi_error(arg)
-    out.type_index = TVMFFIObjectGetTypeIndex((<Object>arg).chandle)
-    out.v_ptr = (<Object>arg).chandle
+    out.type_index = TVMFFIObjectGetTypeIndex((<CObject>arg).chandle)
+    out.v_ptr = (<CObject>arg).chandle
     TVMFFIPyPushTempPyObject(ctx, <PyObject*>arg)
     return 0
 
@@ -595,8 +595,8 @@ cdef int TVMFFIPyArgSetterObjectConvertible_(
     # recursively construct a new map
     cdef object arg = <object>py_arg
     arg = arg.asobject()
-    out.type_index = TVMFFIObjectGetTypeIndex((<Object>arg).chandle)
-    out.v_ptr = (<Object>arg).chandle
+    out.type_index = TVMFFIObjectGetTypeIndex((<CObject>arg).chandle)
+    out.v_ptr = (<CObject>arg).chandle
     TVMFFIPyPushTempPyObject(ctx, <PyObject*>arg)
 
 
@@ -727,7 +727,7 @@ cdef int TVMFFIPyArgSetterFactory_(PyObject* value, TVMFFIPyArgSetter* out) exce
     if isinstance(arg, Tensor):
         out.func = TVMFFIPyArgSetterTensor_
         return 0
-    if isinstance(arg, Object):
+    if isinstance(arg, CObject):
         out.func = TVMFFIPyArgSetterObject_
         return 0
     if isinstance(arg, ObjectRValueRef):
@@ -857,7 +857,7 @@ cdef int TVMFFIPyArgSetterFactory_(PyObject* value, TVMFFIPyArgSetter* out) exce
 # ---------------------------------------------------------------------------------------------
 # Implementation of function calling
 # ---------------------------------------------------------------------------------------------
-cdef class Function(Object):
+cdef class Function(CObject):
     """Callable wrapper around a TVM FFI function.
 
     Instances are obtained by converting Python callables with
@@ -908,7 +908,7 @@ cdef class Function(Object):
         result.v_int64 = 0
         TVMFFIPyFuncCall(
             TVMFFIPyArgSetterFactory_,
-            (<Object>self).chandle, <PyObject*>args,
+            (<CObject>self).chandle, <PyObject*>args,
             &result,
             &c_api_ret_code,
             self.release_gil,
@@ -972,7 +972,7 @@ cdef class Function(Object):
 
         CHECK_CALL(ret_code)
         func = Function.__new__(Function)
-        (<Object>func).chandle = chandle
+        (<CObject>func).chandle = chandle
         return func
 
     @staticmethod
@@ -1026,7 +1026,7 @@ cdef class Function(Object):
             TVMFFIPyMLIRPackedSafeCallDeleter(mlir_packed_safe_call)
         CHECK_CALL(ret_code)
         func = Function.__new__(Function)
-        (<Object>func).chandle = chandle
+        (<CObject>func).chandle = chandle
         return func
 
 
@@ -1039,7 +1039,7 @@ def _register_global_func(name: str, pyfunc: Callable[..., Any] | Function, over
     if not isinstance(pyfunc, Function):
         pyfunc = _convert_to_ffi_func(pyfunc)
 
-    CHECK_CALL(TVMFFIFunctionSetGlobal(name_arg.cptr(), (<Object>pyfunc).chandle, ioverride))
+    CHECK_CALL(TVMFFIFunctionSetGlobal(name_arg.cptr(), (<CObject>pyfunc).chandle, ioverride))
     return pyfunc
 
 
@@ -1050,7 +1050,7 @@ def _get_global_func(name: str, allow_missing: bool):
     CHECK_CALL(TVMFFIFunctionGetGlobal(name_arg.cptr(), &chandle))
     if chandle != NULL:
         ret = Function.__new__(Function)
-        (<Object>ret).chandle = chandle
+        (<CObject>ret).chandle = chandle
         return ret
 
     if allow_missing:
@@ -1105,7 +1105,7 @@ def _convert_to_ffi_func(object pyfunc: Callable[..., Any]) -> Function:
     cdef TVMFFIObjectHandle chandle
     _convert_to_ffi_func_handle(pyfunc, &chandle)
     ret = Function.__new__(Function)
-    (<Object>ret).chandle = chandle
+    (<CObject>ret).chandle = chandle
     return ret
 
 
@@ -1127,7 +1127,7 @@ def _convert_to_opaque_object(object pyobject: Any) -> OpaquePyObject:
     cdef TVMFFIObjectHandle chandle
     _convert_to_opaque_object_handle(pyobject, &chandle)
     ret = OpaquePyObject.__new__(OpaquePyObject)
-    (<Object>ret).chandle = chandle
+    (<CObject>ret).chandle = chandle
     return ret