rust: add derive macro for `Zeroable`

Add a derive proc-macro for the `Zeroable` trait. The macro supports
structs where every field implements the `Zeroable` trait. This way
`unsafe` implementations can be avoided.

The macro is split into two parts:
- a proc-macro to parse generics into impl and ty generics,
- a declarative macro that expands to the impl block.

Suggested-by: Asahi Lina <[email protected]>
Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Added `ignore` to the `lib.rs` example and cleaned trivial nit. ]
Signed-off-by: Miguel Ojeda <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index c28587d68ebc..ae21600970b3 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -18,7 +18,7 @@ pub use core::pin::Pin;
 pub use alloc::{boxed::Box, vec::Vec};
 
 #[doc(no_inline)]
-pub use macros::{module, pin_data, pinned_drop, vtable};
+pub use macros::{module, pin_data, pinned_drop, vtable, Zeroable};
 
 pub use super::build_assert;