1 files changed, 39 insertions, 51 deletions

diff --git a/compiler/rustc_lint/src/expect.rs b/compiler/rustc_lint/src/expect.rs
index d8afba3d505..2450afbca06 100644
--- a/compiler/rustc_lint/src/expect.rs
+++ b/compiler/rustc_lint/src/expect.rs
@@ -1,10 +1,10 @@
-use rustc_data_structures::fx::FxIndexMap;
-use rustc_hir::{HirId, CRATE_OWNER_ID};
+use rustc_data_structures::fx::FxHashSet;
+use rustc_hir::CRATE_OWNER_ID;
 use rustc_middle::lint::LintExpectation;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::builtin::UNFULFILLED_LINT_EXPECTATIONS;
-use rustc_session::lint::{Level, LintExpectationId};
+use rustc_session::lint::LintExpectationId;
 use rustc_span::Symbol;
 
 use crate::lints::{Expectation, ExpectationNote};
@@ -17,43 +17,12 @@ fn lint_expectations(tcx: TyCtxt<'_>, (): ()) -> Vec<(LintExpectationId, LintExp
     let krate = tcx.hir_crate_items(());
 
     let mut expectations = Vec::new();
-    let mut unstable_to_stable_ids = FxIndexMap::default();
 
-    let mut record_stable = |attr_id, hir_id, attr_index| {
-        let expect_id = LintExpectationId::Stable { hir_id, attr_index, lint_index: None };
-        unstable_to_stable_ids.entry(attr_id).or_insert(expect_id);
-    };
-    let mut push_expectations = |owner| {
+    for owner in std::iter::once(CRATE_OWNER_ID).chain(krate.owners()) {
         let lints = tcx.shallow_lint_levels_on(owner);
-        if lints.expectations.is_empty() {
-            return;
-        }
-
         expectations.extend_from_slice(&lints.expectations);
-
-        let attrs = tcx.hir_attrs(owner);
-        for &(local_id, attrs) in attrs.map.iter() {
-            // Some attributes appear multiple times in HIR, to ensure they are correctly taken
-            // into account where they matter. This means we cannot just associate the AttrId to
-            // the first HirId where we see it, but need to check it actually appears in a lint
-            // level.
-            // FIXME(cjgillot): Can this cause an attribute to appear in multiple expectation ids?
-            if !lints.specs.contains_key(&local_id) {
-                continue;
-            }
-            for (attr_index, attr) in attrs.iter().enumerate() {
-                let Some(Level::Expect(_)) = Level::from_attr(attr) else { continue };
-                record_stable(attr.id, HirId { owner, local_id }, attr_index.try_into().unwrap());
-            }
-        }
-    };
-
-    push_expectations(CRATE_OWNER_ID);
-    for owner in krate.owners() {
-        push_expectations(owner);
     }
 
-    tcx.dcx().update_unstable_expectation_id(unstable_to_stable_ids);
     expectations
 }
 
@@ -61,24 +30,43 @@ fn check_expectations(tcx: TyCtxt<'_>, tool_filter: Option<Symbol>) {
     let lint_expectations = tcx.lint_expectations(());
     let fulfilled_expectations = tcx.dcx().steal_fulfilled_expectation_ids();
 
-    for (id, expectation) in lint_expectations {
-        // This check will always be true, since `lint_expectations` only
-        // holds stable ids
-        if let LintExpectationId::Stable { hir_id, .. } = id {
-            if !fulfilled_expectations.contains(id)
-                && tool_filter.map_or(true, |filter| expectation.lint_tool == Some(filter))
-            {
-                let rationale = expectation.reason.map(|rationale| ExpectationNote { rationale });
-                let note = expectation.is_unfulfilled_lint_expectations;
-                tcx.emit_node_span_lint(
-                    UNFULFILLED_LINT_EXPECTATIONS,
-                    *hir_id,
-                    expectation.emission_span,
-                    Expectation { rationale, note },
-                );
+    // Turn a `LintExpectationId` into a `(AttrId, lint_index)` pair.
+    let canonicalize_id = |expect_id: &LintExpectationId| {
+        match *expect_id {
+            LintExpectationId::Unstable { attr_id, lint_index: Some(lint_index) } => {
+                (attr_id, lint_index)
+            }
+            LintExpectationId::Stable { hir_id, attr_index, lint_index: Some(lint_index) } => {
+                // We are an `eval_always` query, so looking at the attribute's `AttrId` is ok.
+                let attr_id = tcx.hir().attrs(hir_id)[attr_index as usize].id;
+                (attr_id, lint_index)
             }
-        } else {
+            _ => panic!("fulfilled expectations must have a lint index"),
+        }
+    };
+
+    let fulfilled_expectations: FxHashSet<_> =
+        fulfilled_expectations.iter().map(canonicalize_id).collect();
+
+    for (expect_id, expectation) in lint_expectations {
+        // This check will always be true, since `lint_expectations` only holds stable ids
+        let LintExpectationId::Stable { hir_id, .. } = expect_id else {
             unreachable!("at this stage all `LintExpectationId`s are stable");
+        };
+
+        let expect_id = canonicalize_id(expect_id);
+
+        if !fulfilled_expectations.contains(&expect_id)
+            && tool_filter.map_or(true, |filter| expectation.lint_tool == Some(filter))
+        {
+            let rationale = expectation.reason.map(|rationale| ExpectationNote { rationale });
+            let note = expectation.is_unfulfilled_lint_expectations;
+            tcx.emit_node_span_lint(
+                UNFULFILLED_LINT_EXPECTATIONS,
+                *hir_id,
+                expectation.emission_span,
+                Expectation { rationale, note },
+            );
         }
     }
 }