1 files changed, 38 insertions, 0 deletions
diff --git a/tests/ui/liveness/liveness-derive.rs b/tests/ui/liveness/liveness-derive.rs
new file mode 100644
index 00000000000..1921d0d72bc
--- /dev/null
+++ b/tests/ui/liveness/liveness-derive.rs
@@ -0,0 +1,38 @@
+// Test for interaction between #[automatically_derived] attribute used by
+// built-in derives and lints generated by liveness pass.
+//
+// edition:2018
+// check-pass
+#![warn(unused)]
+
+pub trait T: Sized {
+    const N: usize;
+    fn t(&self) -> Self;
+}
+
+impl T for u32 {
+    const N: usize = {
+        let a = 0; //~ WARN unused variable: `a`
+        4
+    };
+
+    fn t(&self) -> Self {
+        let b = 16; //~ WARN unused variable: `b`
+        0
+    }
+}
+
+#[automatically_derived]
+impl T for i32 {
+    const N: usize = {
+        let c = 0;
+        4
+    };
+
+    fn t(&self) -> Self {
+        let d = 17;
+        0
+    }
+}
+
+fn main() {}