On 10/23/24 12:38, Manos Pitsidianakis wrote:
Hello Paolo,
On Mon, 21 Oct 2024 19:35, Paolo Bonzini <pbonz...@redhat.com> wrote:
Use the "struct update" syntax to initialize most of the fields to zero,
and simplify the handmade type-checking of $name.
Note: It wasn't meant for type checking but for making sure the linker
doesn't strip the symbol (hence the #[used] attribute). These were left
over when I was debugging linker issues and slapped #[used] everywhere
but they are not needed in this case indeed.
Well, it does do type checking as well, :) otherwise you end up
duck-typing on whether $name as as_ptr(). I guess you are okay with the
change below and the comment:
- name: {
- #[used]
- static _TEMP: &::core::ffi::CStr = $name;
- _TEMP.as_ptr()
- },
+ // use associated function syntax for type checking
+ name: ::core::ffi::CStr::as_ptr($name),
?
info: $prop,
offset: ::core::mem::offset_of!($state, $field)
.try_into()
.expect("Could not fit offset value to type"),
- bitnr: 0,
- bitmask: 0,
set_default: true,
defval: $crate::bindings::Property__bindgen_ty_1 { u:
$defval.into() },
- arrayoffset: 0,
- arrayinfo: ::core::ptr::null(),
- arrayfieldsize: 0,
- link_type: ::core::ptr::null(),
+ ..unsafe {
::core::mem::MaybeUninit::<$crate::bindings::Property>::zeroed().assume_init() }
Call it personal taste but I don't like emulating C's zero initializer
syntax in Rust :) Is it that much trouble to explicitly write down every
field in a macro, anyway? No strong preference here though.
Rust does make generous use of "..Default::default()", so I think it's
more idiomatic to use the struct update syntax. We just cannot use it
here because it's not const-ified.
I'm okay with switching from Zeroable::ZERO to something like
ConstDefault::CONST_DEFAULT; it's basically just a rename. On the other
hand you do rely on "zero-ness" in PL011State::init()... so I thought I
was actually following your style. :)
Paolo
