FP ptr-cast-constness #11317
Description
Summary
.
Lint Name
ptr-cast-constness
Reproducer
I tried this code:
#![allow(invalid_reference_casting)]
fn main() {
let target = 42;
// Make sure raw ptr with raw tag cannot mutate frozen location without breaking the shared ref.
let r#ref = ⌖ // freeze
let ptr = r#ref as *const _ as *mut _; // raw ptr, with raw tag
unsafe { *ptr = 42 }; //~ ERROR: /write access .* only grants SharedReadOnly permission/
let _val = *r#ref;
}I saw this happen:
warning: `as` casting between raw pointers while changing only its constness
--> src/main.rs:7:15
|
7 | let ptr = r#ref as *const _ as *mut _; // raw ptr, with raw tag
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try `pointer::cast_mut`, a safer alternative: `(r#ref as *const _).cast_mut()`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_cast_constness
= note: requested on the command line with `-W clippy::ptr-cast-constness`
rustfix error:
The following errors were reported:
error[E0699]: cannot call a method on a raw pointer with an unknown pointee type
--> src/main.rs:7:35
|
7 | let ptr = (r#ref as *const _).cast_mut(); // raw ptr, with raw tag
| ^^^^^^^^
error: aborting due to previous error
Version
rustc 1.73.0-nightly (f88a8b71c 2023-08-08)
binary: rustc
commit-hash: f88a8b71cebb730cbd5058c45ebcae1d4d9be377
commit-date: 2023-08-08
host: x86_64-unknown-linux-gnu
release: 1.73.0-nightly
LLVM version: 17.0.0
Additional Labels
No response