docs(rustc): Improve discoverable of Cargo docs
In preparing Cargo's blog post for 1.80, I tried to find the documentation for the lint configuration and I couldn't. The link is only visible from the lint itself, which isn't where I started, and the side bar, which was collapsed for me.
The first place I went was the docs for `unexpected_cfgs` because this is configuration for that lint. If using lint configuration were a one off, I could see skipping it here. However, when we discussed this with at least one T-compiler member, there was interest in using this for other lints in the future. To that end, it seems like we should be exposing this with the lint itself.
The second place I checked was the `check-cfg` documentation. This now has a call out for the sub-page.
This is the first time we have a lint with configuration exposed in
`Cargo.toml`.
When this was done, interest was expressed in using this for other cases
in the future.
To this end, we need to make the documentation for the lint
configuration discoverable from the documentation for that lint.
Spruce up the diagnostics of some early lints
Implement the various "*(note to myself) in a follow-up PR we should turn parts of this message into a subdiagnostic (help msg or even struct sugg)*" drive-by comments I left in #124417 during my review.
For context, before #124417, only a few early lints touched/decorated/customized their diagnostic because the former API made it a bit awkward. Likely because of that, things that should've been subdiagnostics were just crammed into the primary message. This PR rectifies this.
Convert `proc_macro_back_compat` lint to an unconditional error.
We still check for the `rental`/`allsorts-rental` crates. But now if they are detected we just emit a fatal error, instead of emitting a warning and providing alternative behaviour.
The original "hack" implementing alternative behaviour was added in #73345.
The lint was added in #83127.
The tracking issue is #83125.
The direct motivation for the change is that providing the alternative behaviour is interfering with #125174 and follow-on work.
r? ``@estebank``
We still check for the `rental`/`allsorts-rental` crates. But now if
they are detected we just emit a fatal error, instead of emitting a
warning and providing alternative behaviour.
The original "hack" implementing alternative behaviour was added
in #73345.
The lint was added in #83127.
The tracking issue is #83125.
The direct motivation for the change is that providing the alternative
behaviour is interfering with #125174 and follow-on work.
Turn remaining non-structural-const-in-pattern lints into hard errors
This completes the implementation of https://github.com/rust-lang/rust/issues/120362 by turning our remaining future-compat lints into hard errors: indirect_structural_match and pointer_structural_match.
They have been future-compat lints for a while (indirect_structural_match for many years, pointer_structural_match since Rust 1.75 (released Dec 28, 2023)), and have shown up in dependency breakage reports since Rust 1.78 (just released on May 2, 2024). I don't expect a lot of code will still depend on them, but we will of course do a crater run.
A lot of cleanup is now possible in const_to_pat, but that is deferred to a later PR.
Fixes https://github.com/rust-lang/rust/issues/70861
Unfortunately, we can't always offer a machine-applicable suggestion when there are subpatterns from macro expansion.
Co-Authored-By: Guillaume Boisseau <Nadrieril@users.noreply.github.com>
Split refining_impl_trait lint into _reachable, _internal variants
As discussed in https://github.com/rust-lang/rust/issues/119535#issuecomment-1909352040:
> We discussed this today in triage and developed a consensus to:
>
> * Add a separate lint against impls that refine a return type defined with RPITIT even when the trait is not crate public.
> * Place that in a lint group along with the analogous crate public lint.
> * Create an issue to solicit feedback on these lints (or perhaps two separate ones).
> * Have the warnings displayed with each lint reference this issue in a similar manner to how we do that today with the required `Self: '0'` bound on GATs.
> * Make a note to review this feedback on 2-3 release cycles.
This points users to https://github.com/rust-lang/rust/issues/121718 to leave feedback.
Fix the conflict problem between the diagnostics fixes of lint `unnecessary_qualification` and `unused_imports`
fixes#121331
For an `item` that triggers lint unnecessary_qualification, if the `use item` which imports this item is also trigger unused import, fixing the two lints at the same time may lead to the problem that the `item` cannot be found.
This PR will avoid reporting lint unnecessary_qualification when conflict occurs.
r? ``@petrochenkov``
Ungate the `UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES` lint
This was missed during stablisation of the `#[diagnostic]` attribute namespace.
Fixes#122446
