Polonius facts: kill loans on Call terminators and StorageDead

1 files changed, 24 insertions, 0 deletions

diff --git a/src/test/ui/nll/polonius/calls-kill-loans.rs b/src/test/ui/nll/polonius/calls-kill-loans.rs
new file mode 100644
index 00000000000..31215714788
--- /dev/null
+++ b/src/test/ui/nll/polonius/calls-kill-loans.rs
@@ -0,0 +1,24 @@
+// `Call` terminators can write to a local which has existing loans
+// and those need to be killed like a regular assignment to a local.
+// This is a simplified version of issue 47680, is correctly accepted
+// by NLL but was incorrectly rejected by Polonius because of these
+// missing `killed` facts.
+
+// build-pass
+// compile-flags: -Z borrowck=mir -Z polonius
+// ignore-compare-mode-nll
+
+struct Thing;
+
+impl Thing {
+    fn next(&mut self) -> &mut Self { unimplemented!() }
+}
+
+fn main() {
+    let mut temp = &mut Thing;
+
+    loop {
+        let v = temp.next();
+        temp = v; // accepted by NLL, was incorrectly rejected by Polonius
+    }
+}