Closed
Description
Summary
When running clippy's latest nightly, the automatically applied suggestion to use a CStr literal (https://rust-lang.github.io/rust-clippy/master/index.html#/manual_c_str_literals) incorrectly applies to projects on pre-2021 editions, causing clippy --fix to output non-compiling code.
Reproducer
I tried this code:
use std::ffi::CStr;
fn main() {
let s = CStr::from_bytes_with_nul(b"test\0").unwrap();
println!("Hello, world: {:?}", s);
}with this Cargo.toml:
[package]
name = "clippy-test"
version = "0.1.0"
edition = "2015"
[dependencies]
I ran cargo +nightly clippy --fix --allow-dirty
I expected to see this happen:
No clippy warnings -- the edition is 2015, so c-str literals are not supported
Instead, this happened:
$ cargo +nightly clippy --fix --allow-dirty
Checking clippy-test v0.1.0 (/Users/miriam/clippy-test)
warning: failed to automatically apply fixes suggested by rustc to crate `clippy_test`
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: expected one of `!`, `.`, `::`, `;`, `?`, `else`, `{`, or an operator, found `"test"`
--> src/main.rs:3:14
|
3 | let s = c"test";
| ^^^^^^ expected one of 8 possible tokens
|
= note: you may be trying to write a c-string literal
= note: c-string literals require Rust 2021 or later
= help: set `edition = "2021"` in `Cargo.toml`
= note: for more on editions, read https://doc.rust-lang.org/edition-guide
warning: unused import: `std::ffi::CStr`
--> src/main.rs:1:5
|
1 | use std::ffi::CStr;
| ^^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
error: aborting due to 1 previous error; 1 warning emitted
Original diagnostics will follow.
warning: calling `CStr::new` with a byte string literal
--> src/main.rs:3:13
|
3 | let s = CStr::from_bytes_with_nul(b"test\0").unwrap();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use a `c""` literal: `c"test"`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_c_str_literals
= note: `#[warn(clippy::manual_c_str_literals)]` on by default
warning: `clippy-test` (bin "clippy-test" test) generated 1 warning (run `cargo clippy --fix --bin "clippy-test" --tests` to apply 1 suggestion)
warning: failed to automatically apply fixes suggested by rustc to crate `clippy_test`
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: expected one of `!`, `.`, `::`, `;`, `?`, `else`, `{`, or an operator, found `"test"`
--> src/main.rs:3:14
|
3 | let s = c"test";
| ^^^^^^ expected one of 8 possible tokens
|
= note: you may be trying to write a c-string literal
= note: c-string literals require Rust 2021 or later
= help: set `edition = "2021"` in `Cargo.toml`
= note: for more on editions, read https://doc.rust-lang.org/edition-guide
warning: unused import: `std::ffi::CStr`
--> src/main.rs:1:5
|
1 | use std::ffi::CStr;
| ^^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
error: aborting due to 1 previous error; 1 warning emitted
Original diagnostics will follow.
warning: `clippy-test` (bin "clippy-test") generated 1 warning (1 duplicate)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
Version
rustc 1.83.0-nightly (eb4e23467 2024-10-09)
binary: rustc
commit-hash: eb4e2346748e1760f74fcaa27b42431e0b95f8f3
commit-date: 2024-10-09
host: aarch64-apple-darwin
release: 1.83.0-nightly
LLVM version: 19.1.1
Additional Labels
No response