Add a test for reset expansion info

2 files changed, 29 insertions, 0 deletions

diff --git a/src/test/ui/hygiene/expansion-info-reset.rs b/src/test/ui/hygiene/expansion-info-reset.rs
new file mode 100644
index 00000000000..d80c1129b29
--- /dev/null
+++ b/src/test/ui/hygiene/expansion-info-reset.rs
@@ -0,0 +1,17 @@
+// 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.
+
+// FIXME: Investigate why expansion info for a single expansion id is reset from
+// `MacroBang(format_args)` to `MacroAttribute(derive(Clone))` (issue #52363).
+
+fn main() {
+    format_args!({ #[derive(Clone)] struct S; });
+    //~^ ERROR format argument must be a string literal
+}
diff --git a/src/test/ui/hygiene/expansion-info-reset.stderr b/src/test/ui/hygiene/expansion-info-reset.stderr
new file mode 100644
index 00000000000..02a7b0d1b02
--- /dev/null
+++ b/src/test/ui/hygiene/expansion-info-reset.stderr
@@ -0,0 +1,12 @@
+error: format argument must be a string literal
+  --> $DIR/expansion-info-reset.rs:15:18
+   |
+LL |     format_args!({ #[derive(Clone)] struct S; });
+   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: you might be missing a string literal to format with
+   |
+LL |     format_args!("{}", { #[derive(Clone)] struct S; });
+   |                  ^^^^^
+
+error: aborting due to previous error
+