1 files changed, 13 insertions, 0 deletions
diff --git a/src/test/ui/conditional-compilation/cfg-attr-empty-is-unused.rs b/src/test/ui/conditional-compilation/cfg-attr-empty-is-unused.rs
new file mode 100644
index 000000000..2600ec7c4
--- /dev/null
+++ b/src/test/ui/conditional-compilation/cfg-attr-empty-is-unused.rs
@@ -0,0 +1,13 @@
+// Check that `#[cfg_attr($PREDICATE,)]` triggers the `unused_attribute` lint.
+
+// compile-flags: --cfg TRUE
+
+#![deny(unused)]
+
+#[cfg_attr(FALSE,)] //~ ERROR `#[cfg_attr]` does not expand to any attributes
+fn _f() {}
+
+#[cfg_attr(TRUE,)] //~ ERROR `#[cfg_attr]` does not expand to any attributes
+fn _g() {}
+
+fn main() {}