Fix rust-lang#8748

b-ncMN · May 29, 2022 · 4b0a829 · 4b0a829
1 parent 39231b4
commit 4b0a829
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Showing 2 changed files with 98 additions and 15 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) {

diff --git a/tests/ui/shadow.stderr b/tests/ui/shadow.stderr
@@ -200,10 +200,10 @@ LL |     if let Some(x) = Some(1) {}
    |                 ^
    |
 note: previous binding is here
-  --> $DIR/shadow.rs:38:9
+  --> $DIR/shadow.rs:42:17
    |
-LL |     let x = 1;
-   |         ^
+LL |             let x = 1;
+   |                 ^
 
 error: `x` shadows a previous, unrelated binding
   --> $DIR/shadow.rs:47:20
@@ -212,10 +212,10 @@ LL |     while let Some(x) = Some(1) {}
    |                    ^
    |
 note: previous binding is here
-  --> $DIR/shadow.rs:38:9
+  --> $DIR/shadow.rs:46:17
    |
-LL |     let x = 1;
-   |         ^
+LL |     if let Some(x) = Some(1) {}
+   |                 ^
 
 error: `x` shadows a previous, unrelated binding
   --> $DIR/shadow.rs:48:15
@@ -224,10 +224,10 @@ LL |     let _ = |[x]: [u32; 1]| {
    |               ^
    |
 note: previous binding is here
-  --> $DIR/shadow.rs:38:9
+  --> $DIR/shadow.rs:47:20
    |
-LL |     let x = 1;
-   |         ^
+LL |     while let Some(x) = Some(1) {}
+   |                    ^
 
 error: `x` shadows a previous, unrelated binding
   --> $DIR/shadow.rs:49:13
@@ -253,6 +253,78 @@ note: previous binding is here
 LL |     let y = Some(1);
    |         ^
 
+error: `x` shadows a previous, unrelated binding
+  --> $DIR/shadow.rs:58:14
+   |
+LL |         Some(x) => {},
+   |              ^
+   |
+note: previous binding is here
+  --> $DIR/shadow.rs:57:14
+   |
+LL |         Some(x) if x == 1 => {},
+   |              ^
+
+error: `x` shadows a previous, unrelated binding
+  --> $DIR/shadow.rs:62:15
+   |
+LL |         [Some(x), None] | [None, Some(x)] => {},
+   |               ^
+   |
+note: previous binding is here
+  --> $DIR/shadow.rs:58:14
+   |
+LL |         Some(x) => {},
+   |              ^
+
+error: `x` shadows a previous, unrelated binding
+  --> $DIR/shadow.rs:65:17
+   |
+LL |     if let Some(x) = Some(1) {
+   |                 ^
+   |
+note: previous binding is here
+  --> $DIR/shadow.rs:62:15
+   |
+LL |         [Some(x), None] | [None, Some(x)] => {},
+   |               ^
+
+error: `x` shadows a previous, unrelated binding
+  --> $DIR/shadow.rs:68:13
+   |
+LL |         let x = 1;
+   |             ^
+   |
+note: previous binding is here
+  --> $DIR/shadow.rs:65:17
+   |
+LL |     if let Some(x) = Some(1) {
+   |                 ^
+
+error: `y` shadows a previous, unrelated binding
+  --> $DIR/shadow.rs:69:13
+   |
+LL |         let y = 1;
+   |             ^
+   |
+note: previous binding is here
+  --> $DIR/shadow.rs:66:13
+   |
+LL |         let y = 1;
+   |             ^
+
+error: `x` shadows a previous, unrelated binding
+  --> $DIR/shadow.rs:71:9
+   |
+LL |     let x = 1;
+   |         ^
+   |
+note: previous binding is here
+  --> $DIR/shadow.rs:68:13
+   |
+LL |         let x = 1;
+   |             ^
+
 error: `_b` shadows a previous, unrelated binding
   --> $DIR/shadow.rs:88:9
    |
@@ -265,5 +337,5 @@ note: previous binding is here
 LL | pub async fn foo2(_a: i32, _b: i64) {
    |                            ^^
 
-error: aborting due to 22 previous errors
+error: aborting due to 28 previous errors