Re: [PATCH 6/6] gdb/python: Add gdb.InferiorThread.__dict__ attribute

[Andrew Burgess <aburgess@redhat.com>]

Tom Tromey <tom@tromey.com> writes:

>>>>>> "Andrew" == Andrew Burgess <aburgess@redhat.com> writes:
>
> Andrew> +  thread_obj->dict = PyDict_New ();
> Andrew> +  if (thread_obj->dict == nullptr)
> Andrew> +    return nullptr;
>
> If this fails...
>
> Andrew>  static void
> Andrew>  thpy_dealloc (PyObject *self)
> Andrew>  {
> Andrew> -  Py_DECREF (((thread_object *) self)->inf_obj);
> Andrew> +  thread_object *thr_obj = (thread_object *) self;
> Andrew> +
> Andrew> +  gdb_assert (thr_obj->inf_obj != nullptr);
> Andrew> +  gdb_assert (thr_obj->dict != nullptr);
> Andrew> +
> Andrew> +  Py_DECREF (thr_obj->inf_obj);
> Andrew> +  Py_DECREF (thr_obj->dict);
>
> ... won't this be called and then crash because dict is NULL?
>
> I am not really sure TBH but other code, like your change in
> py-inferior.c, seems to think this.
>
> I suspect Py_XDECREF should be used instead.
>
> The current call to Py_DECREF isn't a bug because create_thread_object
> avoids creating the thread object when 'inf_obj' would be null.  But,
> the new patch doesn't do this.

Thanks for spotting this.  I'll get this fixed up.

Andrew