permissions_set_readonly_false false positive on Windows

[miles170]

Summary

permissions_set_readonly_false false positive when running Clippy on Windows.

Lint Name

permissions_set_readonly_false

Reproducer

I tried this code on Windows

let metadata = fs::metadata(path).map_err_context(String::new)?;
let mut perms = metadata.permissions();
#[cfg(not(unix))]
perms.set_readonly(false);

I saw this happen:

error: call to `set_readonly` with argument `false`
   --> src\uu\shred\src/shred.rs:475:9
    |
475 |         perms.set_readonly(false);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: on Unix platforms this results in the file being world writable
    = help: you can set the desired permissions using `PermissionsExt`. For more information, see
            https://doc.rust-lang.org/std/os/unix/fs/trait.PermissionsExt.html
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#permissions_set_readonly_false
    = note: `-D clippy::permissions-set-readonly-false` implied by `-D warnings`

I expected to see no error.

See https:/uutils/coreutils/actions/runs/4383223472/jobs/7673213723

Version

rustc 1.68.0 (2c8cc3432 2023-03-06)
binary: rustc
commit-hash: 2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74
commit-date: 2023-03-06
host: x86_64-unknown-linux-gnu
release: 1.68.0
LLVM version: 15.0.6

Additional Labels

No response

[Jarcho]

Checking the repo, it looks like there's nothing in the code to say it's only compiled for Windows. This means that there's no way for clippy to know that there's only one target.

Even with that, I don't think the lint does anything to check if the function call is within a cfg block. This would be a good extension for the lint.

Edit: Looks like you're reporting about the pr, not the current master.

[miles170]

Checking the repo, it looks like there's nothing in the code to say it's only compiled for Windows. This means that there's no way for clippy to know that there's only one target.

Even with that, I don't think the lint does anything to check if the function call is within a cfg block. This would be a good extension for the lint.

Edit: Looks like you're reporting about the pr, not the current master.

Sorry for the incomplete information. I'm indeed reporting about the PR.

I have updated the code where perms.set_readonly(false) is inside the #[cfg(not(unix))] block.

[sylvestre]

it is this PR:
uutils/coreutils#4488