Rollup merge of #56456 - oli-obk:private_impl_trait, r=cramertj

Handle existential types in dead code analysis fixes #55124 r? @cramertj
rust-lang · Dec 4, 2018 · 939de36 · 939de36
2 parents 2d7e7cf + 1fb82b5
commit 939de36
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diff --git a/src/librustc/middle/dead.rs b/src/librustc/middle/dead.rs
@@ -166,6 +166,7 @@ impl<'a, 'tcx> MarkSymbolVisitor<'a, 'tcx> {
                     hir::ItemKind::Fn(..)
                     | hir::ItemKind::Ty(..)
                     | hir::ItemKind::Static(..)
+                    | hir::ItemKind::Existential(..)
                     | hir::ItemKind::Const(..) => {
                         intravisit::walk_item(self, &item);
                     }

diff --git a/src/test/ui/existential_types/private_unused.rs b/src/test/ui/existential_types/private_unused.rs
@@ -0,0 +1,13 @@
+// compile-pass
+
+#[deny(warnings)]
+
+enum Empty { }
+trait Bar<T> {}
+impl Bar<Empty> for () {}
+
+fn boo() -> impl Bar<Empty> {}
+
+fn main() {
+    boo();
+}