sys-base: Expand hard-exit a bit.

diff --git a/sys-base.lisp b/sys-base.lisp
index fdbf4fb..47ef2fb 100644 (file)
--- a/sys-base.lisp
+++ b/sys-base.lisp
@@ -45,9 +45,10 @@ return to the top-level REPL."
         (abort))))
 
 #+cmu
-(defun hard-exit (code)
+(defun hard-exit (&optional (code 0))
   "Stops the program immediately in its tracks.  Does nothing else.  Use
 after fork, for example, to avoid flushing buffers."
+  (declare (type (unsigned-byte 32) code))
   (unix::void-syscall ("_exit" c-call:int) code))
 
 #+cmu