fix tidy

src/libsyntax/feature_gate.rs

@@ -1107,10 +1107,12 @@ pub const BUILTIN_ATTRIBUTES: &'static [(&'static str, AttributeType, AttributeG
 
     // RFC 2070 (deprecated attribute name)
     ("panic_implementation",
-     Normal, Gated(Stability::Deprecated("https://github.com/rust-lang/rust/issues/44489#issuecomment-415140224"),
-                   "panic_implementation",
-                   "This attribute was renamed to `panic_handler`",
-                   cfg_fn!(panic_implementation))),
+     Normal,
+     Gated(Stability::Deprecated("https://github.com/rust-lang/rust/issues/44489\
+                                  #issuecomment-415140224"),
+           "panic_implementation",
+           "This attribute was renamed to `panic_handler`",
+           cfg_fn!(panic_implementation))),
 
     // RFC 2070
     ("panic_handler", Normal, Gated(Stability::Unstable,

src/test/ui/feature-gates/feature-gate-panic-implementation.rs

@@ -0,0 +1,21 @@
+// Copyright 2018 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:-C panic=abort
+
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_implementation] //~ ERROR This attribute was renamed to `panic_handler` (see issue #44489)
+fn panic(info: &PanicInfo) -> ! {
+    loop {}
+}

src/test/ui/feature-gates/feature-gate-panic-implementation.stderr

@@ -0,0 +1,11 @@
+error[E0658]: This attribute was renamed to `panic_handler` (see issue #44489)
+  --> $DIR/feature-gate-panic-implementation.rs:18:1
+   |
+LL | #[panic_implementation] //~ ERROR This attribute was renamed to `panic_handler` (see issue #44489)
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(panic_implementation)] to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.