X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/a588c77a273681e3cdc85d15fc44f3ddb7da9224..1645e4335e58ef3a8f1cafb1834e93760d80d9ae:/src/frontend.lisp

diff --git a/src/frontend.lisp b/src/frontend.lisp
index 0336d1a..68c8a96 100644
--- a/src/frontend.lisp
+++ b/src/frontend.lisp
@@ -7,7 +7,7 @@
 
 ;;;----- Licensing notice ---------------------------------------------------
 ;;;
-;;; This file is part of the Sensble Object Design, an object system for C.
+;;; This file is part of the Sensible Object Design, an object system for C.
 ;;;
 ;;; SOD is free software; you can redistribute it and/or modify
 ;;; it under the terms of the GNU General Public License as published by
@@ -169,6 +169,10 @@
 					     reason))
 			   nil)))))
 
+	      ;; If there are no output types then there's nothing to do.
+	      (unless output-reasons
+		(error "No output types given: nothing to do"))
+
 	      ;; If we're writing the builtin module then now seems like a
 	      ;; good time to do that.
 	      (when builtinsp