Suppress some lints that trigger don't trigger in all cfg's

[Xiphoseer]

This allows a new nightly lint (rust-lang/rust#96150) on some macros that trigger because of how they interact with cfg attributes. From my point-of-view, it didn't make sense to replicate those cfg in an cfg_attr here. There's another case in my patch-5 branch, which might not be a false-positive like these ones.

[Alexhuszagh]

The issue isallow(unused_macro_rules) should produce a warning of unknown_lints if cond is true on anything under nightly-2022-05-12, but should work on nightly-2022-05-12 and above. This means we need some more complex logic, IE, allow(unknown_lints, unused_macro_rules), which I believe I've partially committed as of effaae8.

rust-lexical/lexical-benchmark/input.rs

Line 5 in effaae8

#![allow(dead_code, unused_macros, unknown_lints, unused_macro_rules)]

[Alexhuszagh]

Please replace the #[allow(unused_macros)] changes to also allow unknown_lints, or #[allow(unknown_lints, unused_macros)].

Also please rebase to make sure input.rs doesn't have any conflicts, since I just submitted a similar patch to that file.

[Alexhuszagh]

@Xiphoseer I'm planning a release this Wednesday to fix a bug present in #84 in the float writer, so I was wondering if these changes could be made prior to then to ensure no spurious warnings are present. If not, there are no issues, I would like to give you credit for your work so please take your own time. I appreciate all the work you've done.

[Xiphoseer]

Right, I totally forgot about unknown_lints and that it would affect stable and other nightlies. I had looked at dtolnay/syn@189c60c and didn't realize that this only doesn't need unknown_lints because it's just tests.

I've run the CI checks locally before submitting and they all went through. It looks to me like no CI check actually runs something like RUSTFLAGS=-Dwarnings cargo +stable check. If I run that on the old commit, it obviously errors out. Might be useful to add that as a non-required job.

Also noticed something weird while testing this: The unknown_lints lint doesn't seem to pick up lints within a cfg_attr at all times, filed rust-lang/rust#97094 for that just now. So with this PR merged, I don't think any of them will error, but the one in

rust-lexical/lexical-benchmark/input.rs

Line 5 in 0cf23c8

#![allow(dead_code, unused_macros, unknown_lints, unused_macro_rules)]

is now redundant, the one in

rust-lexical/lexical-write-integer/src/index.rs

Line 8 in 0cf23c8

#![cfg_attr(feature = "compact", allow(unused_macros, unused_macro_rules))]

should error on stable but doesn't and is also duplicate, and I should have removed the two in

rust-lexical/lexical-parse-float/src/index.rs

Line 19 in 0cf23c8

#[allow(unknown_lints, unused_macro_rules)]

and

rust-lexical/lexical-parse-float/src/index.rs

Line 36 in 0cf23c8

#[allow(unknown_lints, unused_macro_rules)]

because you removed the entire macro branch earlier.

[Alexhuszagh]

Right, I totally forgot about unknown_lints and that it would affect stable and other nightlies. I had looked at dtolnay/syn@189c60c and didn't realize that this only doesn't need unknown_lints because it's just tests.

I've run the CI checks locally before submitting and they all went through. It looks to me like no CI check actually runs something like RUSTFLAGS=-Dwarnings cargo +stable check. If I run that on the old commit, it obviously errors out. Might be useful to add that as a non-required job.

Also noticed something weird while testing this: The unknown_lints lint doesn't seem to pick up lints within a cfg_attr at all times, filed rust-lang/rust#97094 for that just now. So with this PR merged, I don't think any of them will error, but the one in

rust-lexical/lexical-benchmark/input.rs

Line 5 in 0cf23c8

#![allow(dead_code, unused_macros, unknown_lints, unused_macro_rules)]

is now redundant, the one in

rust-lexical/lexical-write-integer/src/index.rs

Line 8 in 0cf23c8

#![cfg_attr(feature = "compact", allow(unused_macros, unused_macro_rules))]

should error on stable but doesn't and is also duplicate, and I should have removed the two in

rust-lexical/lexical-parse-float/src/index.rs

Line 19 in 0cf23c8

#[allow(unknown_lints, unused_macro_rules)]

and

rust-lexical/lexical-parse-float/src/index.rs

Line 36 in 0cf23c8

#[allow(unknown_lints, unused_macro_rules)]

because you removed the entire macro branch earlier.

Incredible work, thank you for all your help with this.