Re: [Xen-devel] [PATCH for-next v2 v2 4/5] pygrub: make it build with python 3

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 06/03/2019 17:52, Wei Liu wrote:
> @@ -128,16 +154,25 @@ fsimage_file_dealloc(fsimage_file_t *file)
>       PyObject_DEL(file);
>  }
>  
> +/* Compatibility for 2.5 and earlier */
> +#ifndef PyVarObject_HEAD_INIT
> +#define PyVarObject_HEAD_INIT(type, size) \
> +     PyObject_HEAD_INIT(type) size,
> +#endif
> +
>  static char fsimage_file_type__doc__[] = "Filesystem image file";
>  PyTypeObject fsimage_file_type = {
> -     PyObject_HEAD_INIT(&PyType_Type)
> -     0,                                      /* ob_size */
> +     PyVarObject_HEAD_INIT(&PyType_Type, 0)
>       "xenfsimage.file",                      /* tp_name */
>       sizeof(fsimage_file_t),                 /* tp_size */
>       0,                                      /* tp_itemsize */
>       (destructor) fsimage_file_dealloc,      /* tp_dealloc */
>       0,                                      /* tp_print */
> +#if PY_MAJOR_VERSION < 3
>       (getattrfunc) fsimage_file_getattr,     /* tp_getattr */
> +#else
> +     0,                                      /* tp_getattr */
> +#endif
>       0,                                      /* tp_setattr */
>       0,                                      /* tp_compare */
>       0,                                      /* tp_repr */
> @@ -151,7 +186,16 @@ PyTypeObject fsimage_file_type = {
>       0,                                      /* tp_setattro */
>       0,                                      /* tp_as_buffer */
>       Py_TPFLAGS_DEFAULT,                     /* tp_flags */
> -     fsimage_file_type__doc__,
> +     fsimage_file_type__doc__,               /* tp_doc */
> +#if PY_MAJOR_VERSION >= 3
> +     0,                                      /* tp_traverse */
> +     0,                                      /* tp_clear */
> +     0,                                      /* tp_richcompare */
> +     0,                                      /* tp_weaklistoffset */
> +     0,                                      /* tp_iter */
> +     0,                                      /* tp_iternext */
> +     fsimage_file_methods,                   /* tp_methods */
> +#endif
>       PY_PAD

PY_PAD is very WTF.  I've got no idea why it is necessary in the first
place.

Either way, most of the fields are zero, so why not use named
initialisation?

PyTypeObject fsimage_file_type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    .tp_name = "xenfsimage.file",
    .tp_size = sizeof(fsimage_file_t),
    ...
};


~Andrew

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel