rustc: Polish off `in_external_macro`

This commit polishes off this new function to compile on newer rustc as well as
update and add a suite of test cases to work with this new check for lints.

1 files changed, 24 insertions, 0 deletions

diff --git a/src/test/ui/lint/auxiliary/lints-in-foreign-macros.rs b/src/test/ui/lint/auxiliary/lints-in-foreign-macros.rs
new file mode 100644
index 00000000000..cf8e9c18de3
--- /dev/null
+++ b/src/test/ui/lint/auxiliary/lints-in-foreign-macros.rs
@@ -0,0 +1,24 @@
+// 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.
+
+#[macro_export]
+macro_rules! bar {
+    () => {use std::string::ToString;}
+}
+
+#[macro_export]
+macro_rules! baz {
+    ($i:item) => ($i)
+}
+
+#[macro_export]
+macro_rules! baz2 {
+    ($($i:tt)*) => ($($i)*)
+}