Port lint attributes to attribute parser

[Bryntet]

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Tracking issue: #131229

Ports #[allow], #[deny], #[expect], #[forbid], and #[warn] to being parsed attrs

I tried my best to make this PR as small as possible, it was difficult. I hope it isn't too difficult to review

r? @JonathanBrouwer
r? @jdonszelmann

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in compiler/rustc_hir/src/attrs

cc @jdonszelmann, @JonathanBrouwer

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

cc @jdonszelmann, @JonathanBrouwer

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

[JonathanBrouwer]

@bors try @rust-timer queue

[rustbot]

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.

[Bryntet]

@bors try

[rust-bors]

☀️ Try build successful (CI)
Build commit: c5d8004 (c5d80041ba21dca2acce5d36c44b3f0a06ecc4e6, parent: 69b78537fac74de40f009b076bcbbf54b77683ad)

[rust-log-analyzer]

The job aarch64-gnu-llvm-20-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

/dev/sda15       98M  6.4M   92M   7% /boot/efi
tmpfs           1.6G   16K  1.6G   1% /run/user/1001
================================================================================

Sufficient disk space available (120900768KB >= 52428800KB). Skipping cleanup.
##[group]Run echo "[CI_PR_NUMBER=$num]"
echo "[CI_PR_NUMBER=$num]"
shell: /usr/bin/bash --noprofile --norc -e -o pipefail {0}
---
set -ex

# Run a subset of tests. Used to run tests in parallel in multiple jobs.

# When this job partition is run as part of PR CI, skip tidy to allow revealing more failures. The
# dedicated `tidy` job failing won't block other PR CI jobs from completing, and so tidy failures
# shouldn't inhibit revealing other failures in PR CI jobs.
if [ "$PR_CI_JOB" == "1" ]; then
  echo "PR_CI_JOB set; skipping tidy"
  SKIP_TIDY="--skip tidy"
fi

../x.py --stage 2 test \
  ${SKIP_TIDY:+$SKIP_TIDY} \
  --skip compiler \
  --skip src
#!/bin/bash

set -ex

# Run a subset of tests. Used to run tests in parallel in multiple jobs.

# When this job partition is run as part of PR CI, skip tidy to allow revealing more failures. The
# dedicated `tidy` job failing won't block other PR CI jobs from completing, and so tidy failures
# shouldn't inhibit revealing other failures in PR CI jobs.
if [ "$PR_CI_JOB" == "1" ]; then
  echo "PR_CI_JOB set; skipping tidy"
  SKIP_TIDY="--skip tidy"
fi

../x.py --stage 2 test \
  ${SKIP_TIDY:+$SKIP_TIDY} \
  --skip tests \
  --skip coverage-map \
  --skip coverage-run \
  --skip library \
  --skip tidyselftest
---
Executing "/scripts/stage_2_test_set2.sh"
+ /scripts/stage_2_test_set2.sh
PR_CI_JOB set; skipping tidy
+ '[' 1 == 1 ']'
+ echo 'PR_CI_JOB set; skipping tidy'
+ SKIP_TIDY='--skip tidy'
+ ../x.py --stage 2 test --skip tidy --skip tests --skip coverage-map --skip coverage-run --skip library --skip tidyselftest
##[group]Building bootstrap
    Finished `dev` profile [unoptimized] target(s) in 0.04s
##[endgroup]
downloading https://static.rust-lang.org/dist/2026-01-21/rustfmt-nightly-aarch64-unknown-linux-gnu.tar.xz
---
cannot access a scoped thread local variable without calling `set` first
stack backtrace:
   0: std::panicking::begin_panic
             at /rustc/9b1f8ff42d110b0ca138116745be921df5dc97e7/library/std/src/panicking.rs:761:5
   1: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::with::<<rustc_span::symbol::Symbol>::intern::{closure#0}, rustc_span::symbol::Symbol>
   2: <alloc::vec::into_iter::IntoIter<(alloc::string::String, rustc_lint_defs::Level)> as core::iter::traits::iterator::Iterator>::fold::<(), core::iter::adapters::map::map_fold<(alloc::string::String, rustc_lint_defs::Level), (rustc_span::symbol::Symbol, rustc_lint_defs::Level), (), <rustdoc::config::Options>::from_matches::{closure#1}, core::iter::traits::iterator::Iterator::for_each::call<(rustc_span::symbol::Symbol, rustc_lint_defs::Level), <alloc::vec::Vec<(rustc_span::symbol::Symbol, rustc_lint_defs::Level)>>::extend_trusted<core::iter::adapters::map::Map<alloc::vec::into_iter::IntoIter<(alloc::string::String, rustc_lint_defs::Level)>, <rustdoc::config::Options>::from_matches::{closure#1}>>::{closure#0}>::{closure#0}>::{closure#0}>
   3: <alloc::vec::Vec<(rustc_span::symbol::Symbol, rustc_lint_defs::Level)> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<(rustc_span::symbol::Symbol, rustc_lint_defs::Level), core::iter::adapters::map::Map<alloc::vec::into_iter::IntoIter<(alloc::string::String, rustc_lint_defs::Level)>, <rustdoc::config::Options>::from_matches::{closure#1}>>>::from_iter
   4: <rustdoc::config::Options>::from_matches
   5: rustdoc::main_args
   6: rustc_span::fatal_error::catch_fatal_errors::<rustdoc::main::{closure#1}, ()>
   7: rustdoc::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: the compiler unexpectedly panicked. This is a bug

note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md

note: please make sure that you have updated to the latest nightly

warning: the ICE couldn't be written to `/checkout/rustc-ice-2026-02-26T16_20_17-52313.txt`: Read-only file system (os error 30)

note: rustc 1.95.0-nightly (05ab7d1c8 2026-02-26) running on aarch64-unknown-linux-gnu

note: compiler flags: --crate-type lib -Z --test-args -C embed-bitcode=no -C symbol-mangling-version=v0 -Z annotate-moves -Z randomize-layout -Z unstable-options -Z crate-attr=warn(rust_2018_idioms) -Z force-unstable-if-unmarked -Z crate-attr=doc(rust_logo) -Z crate-attr=doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/") -Z crate-attr=feature(rustdoc_internals)

query stack during panic:
end of query stack
error: doctest failed, to rerun pass `-p rustc_abi --doc`
Bootstrap failed while executing `--stage 2 test --skip tidy --skip tests --skip coverage-map --skip coverage-run --skip library --skip tidyselftest`

[rust-timer]

Finished benchmarking commit (c5d8004): comparison URL.

Overall result: ❌ regressions - BENCHMARK(S) FAILED

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

❗ ❗ ❗ ❗ ❗
Warning ⚠️: The following benchmark(s) failed to build:

• tt-muncher
• unicode-normalization-0.1.24
• image-0.25.6
• helloworld
• large-workspace
• bitmaps-3.2.1
• include-blob
• await-call-tree
• coercions
• eza-0.21.2
• unused-warnings
• clap_derive-4.5.32
• externs
• tuple-stress
• issue-46449
• cranelift-codegen-0.119.0
• projection-caching
• Job failure
• libc-0.2.172
• unify-linearly
• hyper-1.6.0
• nalgebra-0.33.0
• deeply-nested-multi
• ripgrep-14.1.1
• issue-58319
• syn-2.0.101
• issue-88862
• ucd
• wf-projection-stress-65510
• regression-31157
• serde_derive-1.0.219
• serde-1.0.219
• stm32f4-0.15.1
• wg-grammar
• diesel-2.2.10
• serde-1.0.219-threads4
• derive
• deep-vector
• regex-automata-0.4.8
• token-stream-stress
• cargo-0.87.1
• many-assoc-items
• typenum-1.18.0
• ctfe-stress-5
• html5ever-0.31.0
• match-stress

❗ ❗ ❗ ❗ ❗

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)	1.1%	[0.2%, 6.0%]	106
Regressions ❌ (secondary)	0.4%	[0.0%, 1.5%]	96
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	1.1%	[0.2%, 6.0%]	106

Max RSS (memory usage)

Results (primary -0.5%, secondary 2.2%)

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

	mean	range	count
Regressions ❌ (primary)	2.1%	[2.1%, 2.1%]	1
Regressions ❌ (secondary)	4.2%	[1.9%, 6.8%]	6
Improvements ✅ (primary)	-1.4%	[-2.6%, -0.7%]	3
Improvements ✅ (secondary)	-1.9%	[-2.2%, -1.4%]	3
All ❌✅ (primary)	-0.5%	[-2.6%, 2.1%]	4

Cycles

Results (secondary 2.1%)

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

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.1%	[2.1%, 2.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 480.132s -> 482.287s (0.45%)
Artifact size: 395.80 MiB -> 396.08 MiB (0.07%)

[JonathanBrouwer]

@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.