Re: [PATCH 3/3] rust: pl011: Check size of state struct at compile time

[Zhao Liu <zhao1.liu@intel.com>]

> -use std::{ffi::CStr, ptr::addr_of_mut};
> +use std::{ffi::CStr, mem, ptr::addr_of_mut};

maybe mem::size_of (since there're 2 use cases :-))? 

>  
>  use qemu_api::{
> +    bindings,
>      chardev::{CharBackend, Chardev, Event},
> +    static_assert,

This one looks like it breaks the alphabetical ordering (this nit can be
checked and fixed by "cargo +nightly fmt" under rust directory, which is
like checkpatch.pl).

>      impl_vmstate_forward,
>      irq::{IRQState, InterruptSource},
>      memory::{hwaddr, MemoryRegion, MemoryRegionOps, MemoryRegionOpsBuilder},
> @@ -124,6 +126,12 @@ pub struct PL011State {
>      pub migrate_clock: bool,
>  }
>  
> +// Some C users of this device embed its state struct into their own
> +// structs, so the size of the Rust version must not be any larger
> +// than the size of the C one. If this assert triggers you need to
> +// expand the padding_for_rust[] array in the C PL011State struct.
> +static_assert!(mem::size_of::<PL011State>() <= mem::size_of::<bindings::PL011State>());
> +

maybe use qemu_api::bindings::PL011State directly? Because bindings
contains native C structures/functions and their use should not be
encouraged, I think it's better to 'hide' bindings (not list it at the
beginning of the file).

Otherwise,

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>