----- BEGIN CREV PROOF ----- kind: package review version: -1 date: 2022-09-19T17:10:02.580323647+02:00 from: id-type: crev id: YdnEoYtqvbBGv0hhENLDUYmc3tNfm5V5NIG5hCovHyM url: https://git.jcg.re/jcgruenhage/crev-proofs.git package: source: https://crates.io name: atty version: 0.2.14 revision: 7b5df17888997d57c2c1c8f91da1db5691f49953 digest: WJaqS5xu6ORo2px2Rku1ynYYN4TuCdxeS8LR68ngyw4 review: thoroughness: high understanding: high rating: positive flags: unmaintained: true alternatives: - source: https://crates.io name: is-terminal comment: |- One of the more foundational crates found in the dependency tree of a lot of rust programs, because both clap and env_logger pull this in. In my review I've fully read the source code and can confirm that I fully understand what's happening in here. The unix and hermit targets are extremely straight-forward. As for the windows target, that's a bit more complicated, but still manageable in the end. Windows doesn't have a clear API for determining whether something is a (pseudo) TTY, so the heuristics provided by this crate are as good as it's going to get. This crate has quite a few unsafe code sections, but that's sometimes required for providing a safe interface. In this case, we need it because the underlying functions for unix (libc) are unsafe, and the same applies to a bunch of winapi functions used in the heuristics for windows. The bits of unsafe code that's not just wrapping an unsafe function provided by another library are all in the windows heuristics, and involved provisioning buffers that winapi calls can write info back into and some pointer magic. While I couldn't spot an issue with this, a look into the issue tracker revealed that other's have. The buffer creation on the heap is not necessarily aligned properly, meaning that there's a possible soundness issue on windows targets here. Last but not least, we have to talk about maintenance and and alternatives: The soundness issue mentioned above has been known for over a year, with a fix first pushed to a PR shortly after. Even though there's been reviews from well-known rustaceans, the author hasn't merged this PR yet, and in general there hasn't been any relevant activity for a while. An alternative implementation that has been derived from `atty` is `is-terminal`, which has taken this into consideration and has taken over the rest of the implementation from here, with a slightly different API. They're also switching the underlying implementations around, reducing the amount of unsafe. As for why I'm still rating this as positive: With the exception of the potential unsoundness bug on windows, this crate is still okay-ish to be used. Also: Getting rid of it soon is not realistic, because it's in the dependency tree of quite a few widely-used crates. To summarize: Widely used, foundational crate. Except for on windows, this is perfectly fine, on windows there's an unsoundness bug, and there has not been an update or other activity from upstream. `is-terminal` is a good alternative, which was derived from this crate, but includes the fix for the unsoundess bug. ----- SIGN CREV PROOF ----- mY2ODgsozEL4os5aFk0hxL8jH5SHu7awErNdlLHY9UhDL-vLdbDjEIYiD0wFPaTTglTxirK41Jwtokpm4rWyDg ----- END CREV PROOF ----- ----- BEGIN CREV PROOF ----- kind: package review version: -1 date: 2022-09-19T17:10:17.861223964+02:00 from: id-type: crev id: YdnEoYtqvbBGv0hhENLDUYmc3tNfm5V5NIG5hCovHyM url: https://git.jcg.re/jcgruenhage/crev-proofs.git package: source: https://crates.io name: is-terminal version: 0.3.0 revision: 275136008c33722a43724be5a9711af94afa8476 digest: VtFAGa-8B5YOh1SOZHNPgb9KCSb2fcmOUOhnzRqyHKI review: thoroughness: high understanding: high rating: positive comment: |- Following up my review of atty, this is the alternative that I'm recommending. The crate is well-maintained and has the soundness problem from atty fixed. The dependencies have been changed around a bit, with rustix replacing libc, and windows-sys replacing win-api. This means that there's a bit less unsafe code in the library here as well. The API surface changed a bit as well, but I'd claim that the new API is more sensible and allows usage on any file descriptor instead of just stdin/stdout/stderr. Finally, this has one additional dependency, `io-lifetimes`, by the same author. I have not reviewed the implementation, but it's been merged into Rust itself and stabilized with 1.63, so I am not worrying about it too much. ----- SIGN CREV PROOF ----- qermifHP4gqqELsV3vdWnIq0b42d0bAPKqVdQQXzc8n2DTpgIZYBnEfjuDFM88O7sWbpAFqHeJ9v2Z2NUnf7BQ ----- END CREV PROOF -----