Add a feature gate test for #[optimize]

Author: nagisa

src/test/ui/feature-gate-optimize_attribute.rs

@@ -0,0 +1,25 @@
+// 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.
+#![crate_type="rlib"]
+#![optimize(speed)] //~ ERROR #54882
+
+#[optimize(size)] //~ ERROR #54882
+mod module {
+
+#[optimize(size)] //~ ERROR #54882
+fn size() {}
+
+#[optimize(speed)] //~ ERROR #54882
+fn speed() {}
+
+#[optimize(banana)] //~ ERROR #54882
+fn not_known() {}
+
+}

src/test/ui/feature-gate-optimize_attribute.stderr

@@ -0,0 +1,43 @@
+error[E0658]: #[optimize] attribute is an unstable feature (see issue #54882)
+  --> $DIR/feature-gate-optimize_attribute.rs:16:1
+   |
+LL | #[optimize(size)] //~ ERROR #54882
+   | ^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(optimize_attribute)] to the crate attributes to enable
+
+error[E0658]: #[optimize] attribute is an unstable feature (see issue #54882)
+  --> $DIR/feature-gate-optimize_attribute.rs:19:1
+   |
+LL | #[optimize(speed)] //~ ERROR #54882
+   | ^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(optimize_attribute)] to the crate attributes to enable
+
+error[E0658]: #[optimize] attribute is an unstable feature (see issue #54882)
+  --> $DIR/feature-gate-optimize_attribute.rs:22:1
+   |
+LL | #[optimize(banana)] //~ ERROR #54882
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(optimize_attribute)] to the crate attributes to enable
+
+error[E0658]: #[optimize] attribute is an unstable feature (see issue #54882)
+  --> $DIR/feature-gate-optimize_attribute.rs:13:1
+   |
+LL | #[optimize(size)] //~ ERROR #54882
+   | ^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(optimize_attribute)] to the crate attributes to enable
+
+error[E0658]: #[optimize] attribute is an unstable feature (see issue #54882)
+  --> $DIR/feature-gate-optimize_attribute.rs:11:1
+   |
+LL | #![optimize(speed)] //~ ERROR #54882
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(optimize_attribute)] to the crate attributes to enable
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0658`.