Purpose

Aliases for #[allow(...)] local lint permissions/suppressions. You can have multiple aliases, each with its name - semantic.

The problem

Let's say you #[allow(...)] the same standard rustc (prefixless) lint, or clippy:: or rustdoc:: lint, at many places in your code. Even though it's the same lint, you may have different reasons for allowing it. However, #[allow(...)] doesn't carry your intention.

Unfortunately, we can't alias lints with use either. (Why? Because lint names are not (proc) macros, but special compiler symbols.) Of course, you could add a comment, but that's haphazard.

This crate defines one attribute macro per each lint (other than crate-level only lints, more below). Those macros don't take any attribute parameters. They inject #[allow(lint-name-here)] in front of your code.

You can import same macros as many times under as many names you need, for example:

use lint_allow::rustdoc_missing_doc_code_examples as examples_linked;
use lint_allow::rustdoc_missing_doc_code_examples as examples_none_trivial;

Then apply #[exampleslinked], #[examplesnone_trivial], or as you name them, indicating your intention. (Side not: Handling rustdoc:: and clippy:: is not implemented yet. Only standard lints for now.)

Side benefit: Rust would validate the (aliased) names, hence no typos - so you can grep or search for them at anytime. Your team could have a prelude-like module exporting the aliases.

Scope

In scope

All in-built Rust lints (standard rustc lints with no prefix - done; clippy:: & rustdoc:: - TODO see "Help, please").
Both stable and nightly versions of Rust.

Out of scope

Lint groups (like #[allow(unused)]). That's contrary to the purpose of this crate: To differentiate between the use cases of the same lint.
Crate level-only ("inner") attributes. They don't work with #[allow(...)], but only with #![allow(...)] and only at crate level. Chances are you don't have many repetitions of these. You can give thumbs up to rust-lang/rust #54726, but even once that feature is implemented, top level attributes have to come before an use aliases, so you ouldn't alias calls to macros generating #![allow(...)] anyway - so no semantic benefit.
Beta version of rustc specifics ( it's only for 6 weeks). Or, would you help maintain this?
Custom lints (such as with Dylint).

Related issues - give thumbs up, please

Efficient proc macros

This does use procedural macros (specifically: attribute macros). Many: One per lint.

Yes, proc macros often slow compilation down. Proc macros usually use syn and quote crates. Those are powerhouses, which parse & quote the code that a macro can inject. However, their power comes at cost: build time.

But, not so for these macros. This does not parse the new (generated) code into a TokenStream (before it's injected where you use it). Instead, it composes it (through the proc_macro API).

(The tests do have many more dependencies. So don't judge its speed by cargo test, but by cargo build.)

Crates, crates.io and GIT

This project consists of three crates. Two of them will soon be (TODO update) on crates.io: allow and allow_internal. The third one, allow_tests, is not on crates.io, and it is for testing only.

They are all under the same GIT repo, which simplifies maintenance.

Help, please

Compilation failure tests, preferrably with uitest, or with trybuild - but NOT with compilertest-rs). Validate that incorrect lint names make the macros fail. See uitest #57 or trybuild #235.
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Reporting Issues

See coop-rs/allow > issues.

Contributing

See CONTRIBUTING.md.

Testing

Testing is not possible on Windows (to be determined). To minimize human mistakes, tests need to be built on a filesystem that supports symlinks. Of course, the actual crates themselves are platform-independent.

License

Allow project is distributed under the terms of both the MIT license and the Apache License (Version 2.0).