borrow-as-ptr eats parenthesis which break code #13882
Description
Summary
.
Lint Name
borrow-as-ptr
Reproducer
I tried this code:
// Make sure we cannot use raw ptrs that got transmuted from mutable references
// (i.e, no EscapeToRaw happened).
// We could, in principle, do EscapeToRaw lazily to allow this code, but that
// would no alleviate the need for EscapeToRaw (see `ref_raw_int_raw` in
// `run-pass/stacked-borrows.rs`), and thus increase overall complexity.
use std::mem;
fn main() {
let mut x: [i32; 2] = [42, 43];
let _raw: *mut i32 = unsafe { mem::transmute(&mut x[0]) };
// `raw` still carries a tag, so we get another pointer to the same location that does not carry a tag
let raw = (&mut x[1] as *mut i32).wrapping_offset(-1);
unsafe { *raw = 13 }; //~ ERROR: /write access .* tag does not exist in the borrow stack/
}I saw this happen:
cargo +master clippy --fix -- -Wclippy::borrow-as-ptr
Checking o v0.1.0 (/tmp/o)
warning: failed to automatically apply fixes suggested by rustc to crate `o`
after fixes were automatically applied the compiler reported errors within these files:
* src/main.rs
This likely indicates a bug in either rustc or cargo itself,
and we would appreciate a bug report! You're likely to see
a number of compiler warnings after this message which cargo
attempted to fix but failed. If you could open an issue at
https://github.com/rust-lang/rust-clippy/issues
quoting the full output of this command we'd be very appreciative!
Note that you may be able to make some more progress in the near-term
fixing code with the `--broken-code` flag
The following errors were reported:
error[E0599]: no method named `wrapping_offset` found for type `i32` in the current scope
--> src/main.rs:12:29
|
12 | let raw = &raw mut x[1].wrapping_offset(-1);
| ^^^^^^^^^^^^^^^
|
help: there is a method `wrapping_abs` with a similar name, but with different arguments
--> /home/matthias/.rustup/toolchains/master/lib/rustlib/src/rust/library/core/src/num/mod.rs:408:5
|
408 | / int_impl! {
409 | | Self = i32,
410 | | ActualT = i32,
411 | | UnsignedT = u32,
... |
426 | | bound_condition = "",
427 | | }
| |_____^
= note: this error originates in the macro `int_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0599`.
Original diagnostics will follow.
warning: transmute from a reference to a pointer
--> src/main.rs:10:35
|
10 | let _raw: *mut i32 = unsafe { mem::transmute(&mut x[0]) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&mut x[0] as *mut i32`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_transmute
= note: `#[warn(clippy::useless_transmute)]` on by default
warning: borrow as raw pointer
--> src/main.rs:12:15
|
12 | let raw = (&mut x[1] as *mut i32).wrapping_offset(-1);
| ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `&raw mut x[1]`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#borrow_as_ptr
= note: requested on the command line with `-W clippy::borrow-as-ptr`
warning: `o` (bin "o" test) generated 2 warnings (run `cargo clippy --fix --bin "o" --tests` to apply 1 suggestion)
warning: failed to automatically apply fixes suggested by rustc to crate `o`
after fixes were automatically applied the compiler reported errors within these files:
* src/main.rs
This likely indicates a bug in either rustc or cargo itself,
and we would appreciate a bug report! You're likely to see
a number of compiler warnings after this message which cargo
attempted to fix but failed. If you could open an issue at
https://github.com/rust-lang/rust-clippy/issues
quoting the full output of this command we'd be very appreciative!
Note that you may be able to make some more progress in the near-term
fixing code with the `--broken-code` flag
The following errors were reported:
error[E0599]: no method named `wrapping_offset` found for type `i32` in the current scope
--> src/main.rs:12:29
|
12 | let raw = &raw mut x[1].wrapping_offset(-1);
| ^^^^^^^^^^^^^^^
|
help: there is a method `wrapping_abs` with a similar name, but with different arguments
--> /home/matthias/.rustup/toolchains/master/lib/rustlib/src/rust/library/core/src/num/mod.rs:408:5
|
408 | / int_impl! {
409 | | Self = i32,
410 | | ActualT = i32,
411 | | UnsignedT = u32,
... |
426 | | bound_condition = "",
427 | | }
| |_____^
= note: this error originates in the macro `int_impl` (in Nightly builds, run with -Z macro-backtrace for more info)
error: aborting due to 1 previous error
For more information about this error, try `rustc --explain E0599`.
Original diagnostics will follow.
warning: `o` (bin "o") generated 2 warnings (2 duplicates)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.03s
I expected to see this happen:
Version
rustc 1.85.0-nightly (19e75f4fb 2024-12-26)
binary: rustc
commit-hash: 19e75f4fb3f960267996e8788459e97b8769aac7
commit-date: 2024-12-26
host: x86_64-unknown-linux-gnu
release: 1.85.0-nightly
LLVM version: 19.1.6
Additional Labels
No response