Move lint validation to attribute parsing by JonathanBrouwer · Pull Request #164918 · rust-lang/rust

JonathanBrouwer · 2026-10-25T16:08:48Z

This is an alternative approach to #164607

This can be reviewed commit by commit, each commit passes tests.
My goal is for a follow-up to remove lint_name_normalized completely and replace it by a LintId

r? @mejrs

JonathanBrouwer · 2026-10-25T16:10:38Z

-    /// - `custom_tool::blah::bleh` -> `blah::bleh`
-    pub lint_name: Symbol,
+    /// For example, `single_use_lifetime` is changed to `single_use_lifetimes`.
+    pub lint_name_normalized: Symbol,


My goal for a follow-up PR is to change this field from a Symbol that needs to be looked up in LintStore to a LintId. I think this should be possible, but encoding and decoding will be a challenge. I think this PR is already a good step forwards regardless.

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JonathanBrouwer · 2026-10-25T16:11:27Z

 pub use attributes::util::{is_builtin_attr, parse_version};
 pub use context::ShouldEmit;
-pub use diagnostics::ParsedDescription;
+pub use diagnostics::{ParsedDescription, RenamedLintSuggestion, UnknownLintSuggestion};


I'm not sure if people find it cursed to export diagnostic structs such that they can be re-used. I like it

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JonathanBrouwer · 2026-10-25T16:11:46Z

            CRATE_NODE_ID,
            Some(self.features),
            ShouldEmit::ErrorsAndLints { recovery: Recovery::Allowed },
+            None,


This was wrong before! Oops!

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JonathanBrouwer · 2026-10-25T16:12:11Z

                                    ),
                                };

+                                let lint_name_normalized = if let Some((_lint_ids, new_lint_name)) =


Note that we already have the lint_ids here! We just need to figure out how to encode & decode them in a follow-up PR!

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JonathanBrouwer · 2026-10-25T16:17:06Z

@bors try @rust-timer queue

Move lint validation to attribute parsing

rustbot · 2026-10-25T16:17:15Z

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann

Some changes occurred in compiler/rustc_attr_ir

cc @jdonszelmann

clippy is developed in its own repository. If possible, consider making this change to rust-lang/rust-clippy instead.

cc @rust-lang/clippy

Some changes occurred in compiler/rustc_passes/src/check_attr.rs

cc @jdonszelmann

rust-bors · 2026-10-25T17:16:11Z

☀️ Try build successful (CI)
Build commit: 00e2c28 (00e2c28e2c046bbcd149ca7f1bf88c8cfc9e8875)
Base parent: dc44e7f (dc44e7f2c436b6041742e138b9c2176f093196d5)

rust-timer · 2026-10-25T18:05:43Z

Finished benchmarking commit (00e2c28): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@bors rollup=iffy rustc-perf
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.3%	[-0.3%, -0.1%]	9
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.3%	[-0.3%, -0.1%]	9

Max RSS (memory usage)

Results (primary -0.5%, secondary -0.7%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.5%, 0.9%]	5
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.4%	[-3.1%, -0.5%]	6
Improvements ✅ (secondary)	-0.7%	[-0.7%, -0.7%]	1
All ❌✅ (primary)	-0.5%	[-3.1%, 0.9%]	11

Cycles

Results (primary 0.4%, secondary 0.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	0.9%	[0.5%, 2.1%]	9
Regressions ❌ (secondary)	1.3%	[0.5%, 3.4%]	5
Improvements ✅ (primary)	-1.0%	[-1.7%, -0.7%]	3
Improvements ✅ (secondary)	-1.3%	[-2.1%, -0.5%]	2
All ❌✅ (primary)	0.4%	[-1.7%, 2.1%]	12

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 487.351s -> 486.11s (-0.25%)
Artifact size: 405.87 MiB -> 406.01 MiB (0.03%)

We will need the `lint_tools` in the next commits

This is a lot of code being moved around, but not much of the logic changes. I changed some stuff though, so I recommend reviewing the logic side by side.

rustbot · 2026-10-26T14:33:51Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

mejrs

I don't think this change is correct, it means lowering ast to hir depends on what lints have been registered. Does this mean cargo clippy and cargo check could produce different artefacts? What happens when rust-analyzer decides to implement its own lints? (it's possible, it's a pregistered tool).

Can you talk to people more knowledgeable about this and get them to sign off on this? The people that are working on sharing cargo build caches probably have opinions about this.

@rustbot author

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JonathanBrouwer commented Oct 25, 2026

View reviewed changes

rustbot assigned mejrs Oct 25, 2026