1 files changed, 103 insertions, 0 deletions
diff --git a/src/test/ui/drop/issue-30018-nopanic.rs b/src/test/ui/drop/issue-30018-nopanic.rs
new file mode 100644
index 000000000..291bab273
--- /dev/null
+++ b/src/test/ui/drop/issue-30018-nopanic.rs
@@ -0,0 +1,103 @@
+// run-pass
+#![allow(unreachable_code)]
+// More thorough regression test for Issues #30018 and #30822. This
+// attempts to explore different ways that array element construction
+// (for both scratch arrays and non-scratch ones) interacts with
+// breaks in the control-flow, in terms of the order of evaluation of
+// the destructors (which may change; see RFC Issue 744) and the
+// number of times that the destructor evaluates for each value (which
+// should never exceed 1; this latter case is what #30822 is about).
+
+use std::cell::RefCell;
+
+struct D<'a>(&'a RefCell<Vec<i32>>, i32);
+
+impl<'a> Drop for D<'a> {
+    fn drop(&mut self) {
+        println!("Dropping D({})", self.1);
+        (self.0).borrow_mut().push(self.1);
+    }
+}
+
+fn main() {
+    println!("Start");
+    break_during_elem();
+    break_after_whole();
+    println!("Finis");
+}
+
+fn break_during_elem() {
+    let log = &RefCell::new(Vec::new());
+
+    // CASE 1: Fixed-size array itself is stored in _r slot.
+    loop {
+        let _r = [D(log, 10),
+                  D(log, 11),
+                  { D(log, 12); break; },
+                  D(log, 13)];
+    }
+    assert_eq!(&log.borrow()[..], &[12, 11, 10]);
+    log.borrow_mut().clear();
+
+    // CASE 2: Slice (borrow of array) is stored in _r slot.
+    // This is the case that is actually being reported in #30018.
+    loop {
+        let _r = &[D(log, 20),
+                   D(log, 21),
+                   { D(log, 22); break; },
+                   D(log, 23)];
+    }
+    assert_eq!(&log.borrow()[..], &[22, 21, 20]);
+    log.borrow_mut().clear();
+
+    // CASE 3: (Borrow of) slice-index of array is stored in _r slot.
+    loop {
+        let _r = &[D(log, 30),
+                  D(log, 31),
+                  { D(log, 32); break; },
+                  D(log, 33)][..];
+    }
+    assert_eq!(&log.borrow()[..], &[32, 31, 30]);
+    log.borrow_mut().clear();
+}
+
+// The purpose of these functions is to test what happens when we
+// panic after an array has been constructed in its entirety.
+//
+// It is meant to act as proof that we still need to continue
+// scheduling the destruction of an array even after we've scheduling
+// drop for its elements during construction; the latter is tested by
+// `fn break_during_elem()`.
+fn break_after_whole() {
+    let log = &RefCell::new(Vec::new());
+
+    // CASE 1: Fixed-size array itself is stored in _r slot.
+    loop {
+        let _r = [D(log, 10),
+                  D(log, 11),
+                  D(log, 12)];
+        break;
+    }
+    assert_eq!(&log.borrow()[..], &[10, 11, 12]);
+    log.borrow_mut().clear();
+
+    // CASE 2: Slice (borrow of array) is stored in _r slot.
+    loop {
+        let _r = &[D(log, 20),
+                   D(log, 21),
+                   D(log, 22)];
+        break;
+    }
+    assert_eq!(&log.borrow()[..], &[20, 21, 22]);
+    log.borrow_mut().clear();
+
+    // CASE 3: (Borrow of) slice-index of array is stored in _r slot.
+    loop {
+        let _r = &[D(log, 30),
+                   D(log, 31),
+                   D(log, 32)][..];
+        break;
+    }
+    assert_eq!(&log.borrow()[..], &[30, 31, 32]);
+    log.borrow_mut().clear();
+}