Fix `len_zero` ICE
diff --git a/clippy_lints/src/len_zero.rs b/clippy_lints/src/len_zero.rs
index 798d48f..e862240 100644
--- a/clippy_lints/src/len_zero.rs
+++ b/clippy_lints/src/len_zero.rs
@@ -104,34 +104,28 @@
}
// fill the set with current and super traits
- fn fill_trait_set<'a, 'b: 'a>(traitt: &'b Item, set: &'a mut HashSet<&'b Item>, cx: &'b LateContext) {
+ fn fill_trait_set(traitt: DefId, set: &mut HashSet<DefId>, cx: &LateContext) {
if set.insert(traitt) {
- if let ItemTrait(.., ref ty_param_bounds, _) = traitt.node {
- for ty_param_bound in ty_param_bounds {
- if let TraitTyParamBound(ref poly_trait_ref, _) = *ty_param_bound {
- let super_trait_node_id = cx.tcx
- .hir
- .as_local_node_id(poly_trait_ref.trait_ref.path.def.def_id())
- .expect("the DefId is local, the NodeId should be available");
- let super_trait = cx.tcx.hir.expect_item(super_trait_node_id);
- fill_trait_set(super_trait, set, cx);
- }
- }
+ for supertrait in ::rustc::traits::supertrait_def_ids(cx.tcx, traitt) {
+ fill_trait_set(supertrait, set, cx);
}
}
}
if cx.access_levels.is_exported(visited_trait.id) && trait_items.iter().any(|i| is_named_self(cx, i, "len")) {
let mut current_and_super_traits = HashSet::new();
- fill_trait_set(visited_trait, &mut current_and_super_traits, cx);
+ let visited_trait_def_id = cx.tcx.hir.local_def_id(visited_trait.id);
+ fill_trait_set(visited_trait_def_id, &mut current_and_super_traits, cx);
let is_empty_method_found = current_and_super_traits
.iter()
- .flat_map(|i| match i.node {
- ItemTrait(.., ref trait_items) => trait_items.iter(),
- _ => bug!("should only handle traits"),
- })
- .any(|i| is_named_self(cx, i, "is_empty"));
+ .flat_map(|&i| cx.tcx.associated_items(i))
+ .any(|i| {
+ i.kind == ty::AssociatedKind::Method &&
+ i.method_has_self_argument &&
+ i.name == "is_empty" &&
+ cx.tcx.fn_sig(i.def_id).inputs().skip_binder().len() == 1
+ });
if !is_empty_method_found {
span_lint(
diff --git a/tests/ui/len_zero.rs b/tests/ui/len_zero.rs
index e0e735a..9c66d5a 100644
--- a/tests/ui/len_zero.rs
+++ b/tests/ui/len_zero.rs
@@ -182,3 +182,10 @@
if b.len() != 0 {
}
}
+
+// this used to ICE
+pub trait Foo: Sized {}
+
+pub trait DependsOnFoo: Foo {
+ fn len(&mut self) -> usize;
+}
diff --git a/tests/ui/len_zero.stderr b/tests/ui/len_zero.stderr
index 5e39618..6e3cf1b 100644
--- a/tests/ui/len_zero.stderr
+++ b/tests/ui/len_zero.stderr
@@ -86,5 +86,13 @@
182 | if b.len() != 0 {
| ^^^^^^^^^^^^ help: using `is_empty` is more concise: `!b.is_empty()`
-error: aborting due to 11 previous errors
+error: trait `DependsOnFoo` has a `len` method but no (possibly inherited) `is_empty` method
+ --> $DIR/len_zero.rs:189:1
+ |
+189 | / pub trait DependsOnFoo: Foo {
+190 | | fn len(&mut self) -> usize;
+191 | | }
+ | |_^
+
+error: aborting due to 12 previous errors
