;;;; A dyn value produced inside a defer, on a function a transfer leaves
;;;; through rather than returns from.
;;;;
;;;; This is here for the root count and not for the arithmetic. A defer appears
;;;; twice in the typed IR — spliced into the body for the normal path, and
;;;; again in fdefers for the path a handled condition unwinds along — so the
;;;; emitter produces two copies of every dyn temporary inside one. Counting
;;;; only the body left the second copy's temporaries in slots the collector had
;;;; never been told about: the pushes and the pops still balanced, so nothing
;;;; failed, and the values were simply invisible.
;;;;
;;;; Nothing the stub does can show that, because it never collects. What shows
;;;; it is the emitted IR — a fallback slot is spelled %dx and a rooted one %dr,
;;;; and the fix is the absence of the former.

(defstruct Boom [n i64])

(defn inner [x] dyn
  (defer (print (+ x 1000)) (print "\n"))
  (restart-case
    (error (Boom {.n 1}))
    (give [] 0))
  (+ x 1))

(defn main [] ()
  (handler-bind [(Boom [b] (invoke-restart 'give))]
    (print (inner 5))
    (print "\n")))