1 files changed, 17 insertions, 0 deletions
diff --git a/tests/ui/parser/underscore-suffix-for-string.rs b/tests/ui/parser/underscore-suffix-for-string.rs
new file mode 100644
index 00000000000..bd260752e04
--- /dev/null
+++ b/tests/ui/parser/underscore-suffix-for-string.rs
@@ -0,0 +1,17 @@
+macro_rules! sink {
+    ($tt:tt) => {()}
+}
+
+fn main() {
+    let _ = "Foo"_;
+    //~^ ERROR underscore literal suffix is not allowed
+
+    // This is ok, because `__` is a valid identifier and the macro consumes it
+    // before proper parsing happens.
+    let _ = sink!("Foo"__);
+
+    // This is not ok, even as an input to a macro, because the `_` suffix is
+    // never allowed.
+    sink!("Foo"_);
+    //~^ ERROR underscore literal suffix is not allowed
+}