Closed
Description
Excerpt of original output of cargo clippy --fix in console-rs/indicatif#547, which suggested to create an issue here:
Checking indicatif v0.17.4 (C:\foresterre\indicatif)
warning: failed to automatically apply fixes suggested by rustc to crate `multi_autodrop`
after fixes were automatically applied the compiler reported errors within these files:
* tests\multi-autodrop.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/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
I tried this code (can probably be made more minimal):
use std::sync::{atomic::AtomicU32, atomic::Ordering, Arc, Mutex, RwLock};
// Reproduction derived from indicatif::MultiProgress and ProgressBar where this Clippy suggestion was found.
// With Clippy 0.1.71 (2023-06-01 d59363a)
// With Rust 1.70.0
#[derive(Clone)]
struct MultiProgress {
state: Arc<RwLock<State>>,
}
impl Default for MultiProgress {
fn default() -> Self {
Self {
state: Arc::new(RwLock::new(State)),
}
}
}
impl MultiProgress {
fn add(&self, pb: ProgressBar) -> ProgressBar {
let state = self.state.write().unwrap();
drop(state);
pb.set_remote(self.state.clone());
pb
}
}
#[derive(Clone)]
struct ProgressBar {
value: Arc<AtomicU32>,
remote: Arc<Mutex<Arc<RwLock<State>>>>,
}
impl Default for ProgressBar {
fn default() -> Self {
Self {
value: Arc::new(AtomicU32::new(0)),
remote: Arc::new(Mutex::new(Arc::new(RwLock::new(State)))),
}
}
}
impl ProgressBar {
fn set_remote(&self, state: Arc<RwLock<State>>) {
*self.remote.lock().unwrap() = state;
}
fn inc(&self, delta: u32) {
self.value.fetch_add(delta, Ordering::SeqCst);
}
fn reset(&self) {
self.value.fetch_add(0, Ordering::SeqCst);
}
}
struct State;
fn main() {
let pb = {
let m = MultiProgress::default();
m.add(ProgressBar::default())
// m is dropped here
};
{
// Clippy faults here: it suggests to remove the clone.
let pb2 = pb.clone();
for _ in 0..10 {
pb2.inc(1);
}
}
pb.reset();
}Running cargo clippy:
hecking playground v0.0.1 (/playground)
warning: redundant clone
--> src/main.rs:70:21
|
70 | let pb2 = pb.clone();
| ^^^^^^^^ help: remove this
|
note: cloned value is neither consumed nor mutated
--> src/main.rs:70:19
|
70 | let pb2 = pb.clone();
| ^^^^^^^^^^
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_clone
= note: `#[warn(clippy::redundant_clone)]` on by default
warning: `playground` (bin "playground") generated 1 warning (run `cargo clippy --fix --bin "playground"` to apply 1 suggestion)
Finished dev [unoptimized + debuginfo] target(s) in 0.42s
When applying the suggestion:
Checking playground v0.0.1 (/playground)
error[E0382]: borrow of moved value: `pb`
--> src/main.rs:76:5
|
62 | let pb = {
| -- move occurs because `pb` has type `ProgressBar`, which does not implement the `Copy` trait
...
70 | let pb2 = pb;
| -- value moved here
...
76 | pb.reset();
| ^^^^^^^^^^ value borrowed here after move
|
help: consider cloning the value if the performance cost is acceptable
|
70 | let pb2 = pb.clone();
| ++++++++
For more information about this error, try `rustc --explain E0382`.
error: could not compile `playground` (bin "playground") due to previous error
Meta
rustc --version --verbose:
rustc 1.70.0 (90c541806 2023-05-31)
binary: rustc
commit-hash: 90c541806f23a127002de5b4038be731ba1458ca
commit-date: 2023-05-31
host: x86_64-pc-windows-msvc
release: 1.70.0
LLVM version: 16.0.2
cargo clippy --version --verbose:
clippy 0.1.70 (90c54180 2023-05-31)