+
+(defun replace-dynamic-extent-object (obj)
+ (if (stack-allocated-p obj)
+ (make-unprintable-object
+ (handler-case
+ (format nil "dynamic-extent: ~S" obj)
+ (error ()
+ "error printing dynamic-extent object")))
+ obj))
+
+(defun stack-allocated-p (obj)
+ "Returns T if OBJ is allocated on the stack of the current
+thread, NIL otherwise."
+ (with-pinned-objects (obj)
+ (let ((sap (int-sap (get-lisp-obj-address obj))))
+ (when (sb!vm:control-stack-pointer-valid-p sap nil)
+ t))))