(c-macro-expansion): If the CPP output is empty, just show error messages.

diff --git a/lisp/progmodes/cmacexp.el b/lisp/progmodes/cmacexp.el
index daaa0109bb0bbc3c0020ff12025e25af4e2ebfce..a84aa5eb091f6370e3310b590873874a0e457539 100644 (file)
--- a/lisp/progmodes/cmacexp.el
+++ b/lisp/progmodes/cmacexp.el
@@ -3,7 +3,7 @@
 ;; Copyright (C) 1992, 1994 Free Software Foundation, Inc.
 
 ;; Author: Francesco Potorti` <pot@cnuce.cnr.it>
-;; Version: $Id: cmacexp.el,v 1.14 1994/05/03 22:17:03 kwzh Exp rms $
+;; Version: $Id: cmacexp.el,v 1.15 1994/08/07 17:23:44 rms Exp rms $
 ;; Adapted-By: ESR
 ;; Keywords: c
 
@@ -305,11 +305,14 @@ Optional arg DISPLAY non-nil means show messages in the echo area."
                (call-process-region 1 (point-max) "sh" t t nil "-c"
                                     (concat cppcommand " 2>" tempname)))
          (if display (message (concat mymsg "done")))
-         ;; Find and delete the mark of the start of the expansion.
-         ;; Look for `# nn "file.c"' lines and delete them.
-         (goto-char (point-min))
-         (search-forward startmarker)
-         (delete-region 1 (point))
+         (if (= (buffer-size) 0)
+             ;; Empty output is normal after a fatal error.
+             (insert "\nPreprocessor produced no output\n")
+           ;; Find and delete the mark of the start of the expansion.
+           ;; Look for `# nn "file.c"' lines and delete them.
+           (goto-char (point-min))
+           (search-forward startmarker)
+           (delete-region 1 (point)))
          (while (re-search-forward (concat "^# [0-9]+ \""
                                            (regexp-quote filename)
                                            "\"") nil t)