Add a missing fmt::Debug impl lint

Closes #20855

1 files changed, 48 insertions, 0 deletions

diff --git a/src/test/compile-fail/missing_debug_impls.rs b/src/test/compile-fail/missing_debug_impls.rs
new file mode 100644
index 00000000000..4adae2f3680
--- /dev/null
+++ b/src/test/compile-fail/missing_debug_impls.rs
@@ -0,0 +1,48 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-flags: --crate-type lib
+#![deny(missing_debug_implementations)]
+#![allow(unused, unstable, missing_copy_implementations)]
+
+use std::fmt;
+
+pub enum A {} //~ ERROR type does not implement `fmt::Debug`
+
+#[derive(Debug)]
+pub enum B {}
+
+pub enum C {}
+
+impl fmt::Debug for C {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        Ok(())
+    }
+}
+
+pub struct Foo; //~ ERROR type does not implement `fmt::Debug`
+
+#[derive(Debug)]
+pub struct Bar;
+
+pub struct Baz;
+
+impl fmt::Debug for Baz {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        Ok(())
+    }
+}
+
+struct PrivateStruct;
+
+enum PrivateEnum {}
+
+#[derive(Debug)]
+struct GenericType<T>(T);