From 8bf33c213fe752a5a9f6fbc2594316dcbdd5a262 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Thu, 13 Mar 2025 00:22:16 +0000
Subject: [PATCH] Visit PatField when collecting lint levels

---
 compiler/rustc_lint/src/levels.rs             |  5 +++++
 .../lint/unused/unused-field-in-pat-field.rs  | 21 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 tests/ui/lint/unused/unused-field-in-pat-field.rs

diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 4ede9b4408798..42b771471d08f 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -299,6 +299,11 @@ impl<'tcx> Visitor<'tcx> for LintLevelsBuilder<'_, LintLevelQueryMap<'tcx>> {
         intravisit::walk_expr(self, e);
     }
 
+    fn visit_pat_field(&mut self, f: &'tcx hir::PatField<'tcx>) -> Self::Result {
+        self.add_id(f.hir_id);
+        intravisit::walk_pat_field(self, f);
+    }
+
     fn visit_expr_field(&mut self, f: &'tcx hir::ExprField<'tcx>) {
         self.add_id(f.hir_id);
         intravisit::walk_expr_field(self, f);
diff --git a/tests/ui/lint/unused/unused-field-in-pat-field.rs b/tests/ui/lint/unused/unused-field-in-pat-field.rs
new file mode 100644
index 0000000000000..34959a1023f95
--- /dev/null
+++ b/tests/ui/lint/unused/unused-field-in-pat-field.rs
@@ -0,0 +1,21 @@
+//@ check-pass
+
+// Ensure we collect lint levels from pat fields in structs.
+
+#![deny(unused_variables)]
+
+pub struct Foo {
+    bar: u32,
+    baz: u32,
+}
+
+pub fn test(foo: Foo) {
+    let Foo {
+        #[allow(unused_variables)]
+        bar,
+        #[allow(unused_variables)]
+        baz,
+    } = foo;
+}
+
+fn main() {}