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Fix build error that assigning to &T is undefined behavior #59

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Fix build error that assigning to &T is undefined behavior #59

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3 changes: 2 additions & 1 deletion src/serial.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@
//! let received = block!(rx.read()).unwrap();
//! ```

use core::cell::UnsafeCell;
use core::marker::PhantomData;
use core::ptr;

Expand Down Expand Up @@ -419,7 +420,7 @@ impl<USART: UsartX> crate::hal::serial::Write<u8> for Tx<USART> {
// NOTE(unsafe) atomic write to stateless register
// NOTE(write_volatile) 8-bit write that's not possible through the svd2rust API
unsafe {
ptr::write_volatile(&(*USART::ptr()).data as *const _ as *mut _, byte)
ptr::write_volatile(UnsafeCell::raw_get(&(*USART::ptr()).data as *const _ as _), byte);
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The issue here is the creation of a reference, but creating a reference here is useless, it's not required, using the addr_of_mut! macro should create a pointer to be field without a reference:

Suggested change
ptr::write_volatile(UnsafeCell::raw_get(&(*USART::ptr()).data as *const _ as _), byte);
ptr::write_volatile(addr_of_mut!((*USART::ptr()).data), byte);

Note that the lint is best-effort, it can be defeated, and I think that's one of the pattern.

}
Ok(())
} else {
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