1 files changed, 55 insertions, 0 deletions
diff --git a/tests/ui/macros/panic-temporaries-2018.rs b/tests/ui/macros/panic-temporaries-2018.rs
new file mode 100644
index 000000000..d914df380
--- /dev/null
+++ b/tests/ui/macros/panic-temporaries-2018.rs
@@ -0,0 +1,55 @@
+// check-pass
+// edition:2018
+
+#![allow(non_fmt_panics, unreachable_code)]
+
+use std::fmt::{self, Display};
+use std::marker::PhantomData;
+
+struct NotSend {
+    marker: PhantomData<*const u8>,
+}
+
+const NOT_SEND: NotSend = NotSend { marker: PhantomData };
+
+impl Display for NotSend {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("this value does not implement Send")
+    }
+}
+
+async fn f(_: u8) {}
+
+// Exercises this matcher in panic_2015:
+// ($fmt:expr, $($arg:tt)+) => $crate::panicking::panic_fmt(...)
+async fn panic_fmt() {
+    // Panic returns `!`, so the await is never reached, and in particular the
+    // temporaries inside the formatting machinery are not still alive at the
+    // await point.
+    let todo = "...";
+    f(panic!("not yet implemented: {}", todo)).await;
+}
+
+// Exercises ("{}", $arg:expr) => $crate::panicking::panic_display(&$arg)
+async fn panic_display() {
+    f(panic!("{}", NOT_SEND)).await;
+}
+
+// Exercises ($msg:expr) => $crate::panicking::panic_str($msg)
+async fn panic_str() {
+    f(panic!((NOT_SEND, "...").1)).await;
+}
+
+// Exercises ($msg:expr) => $crate::panicking::unreachable_display(&$msg)
+async fn unreachable_display() {
+    f(unreachable!(NOT_SEND)).await;
+}
+
+fn require_send(_: impl Send) {}
+
+fn main() {
+    require_send(panic_fmt());
+    require_send(panic_display());
+    require_send(panic_str());
+    require_send(unreachable_display());
+}