Fix rust-lang#8748

b-ncMN · May 29, 2022 · 5841dbf · 5841dbf
1 parent 39231b4
commit 5841dbf
Showing 1 changed file with 16 additions and 5 deletions.
diff --git a/clippy_lints/src/shadow.rs b/clippy_lints/src/shadow.rs
@@ -126,7 +126,7 @@ impl<'tcx> LateLintPass<'tcx> for Shadow {
                 return;
             }
 
-            if is_shadow(cx, owner, prev, local_id) {
+            if is_shadow(cx, owner, prev, local_id).is_ok() {
                 let prev_hir_id = HirId { owner, local_id: prev };
                 lint_shadow(cx, pat, prev_hir_id, ident.span);
                 // only lint against the "nearest" shadowed binding
@@ -158,11 +158,22 @@ impl<'tcx> LateLintPass<'tcx> for Shadow {
     }
 }
 
-fn is_shadow(cx: &LateContext<'_>, owner: LocalDefId, first: ItemLocalId, second: ItemLocalId) -> bool {
+type Result<T> = std::result::Result<T, LifetimeError>;
+
+#[derive(Debug, Clone)]
+struct LifetimeError;
+
+impl std::fmt::Display for LifetimeError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Invalid lifetime")
+    }
+}
+
+fn is_shadow(cx: &LateContext<'_>, owner: LocalDefId, first: ItemLocalId, second: ItemLocalId) -> Result<bool> {
     let scope_tree = cx.tcx.region_scope_tree(owner.to_def_id());
-    let first_scope = scope_tree.var_scope(first).unwrap();
-    let second_scope = scope_tree.var_scope(second).unwrap();
-    scope_tree.is_subscope_of(second_scope, first_scope)
+    let first_scope = scope_tree.var_scope(first).ok_or(LifetimeError)?;
+    let second_scope = scope_tree.var_scope(second).ok_or(LifetimeError)?;
+    Ok(scope_tree.is_subscope_of(second_scope, first_scope))
 }
 
 fn lint_shadow(cx: &LateContext<'_>, pat: &Pat<'_>, shadowed: HirId, span: Span) {