Doc fixes.

(c-macro-expansion): Capture and display CPP error messages.

1 files changed, 18 insertions, 7 deletions

diff --git a/lisp/progmodes/cmacexp.el b/lisp/progmodes/cmacexp.el
index 6c615c4d996..daaa0109bb0 100644
--- 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 1.13 1994/04/21 18:40:14 rms Exp kwzh $
+;; Version: $Id: cmacexp.el,v 1.14 1994/05/03 22:17:03 kwzh Exp rms $
 ;; Adapted-By: ESR
 ;; Keywords: c
 
@@ -96,11 +96,11 @@
 (defvar c-macro-preprocessor "/lib/cpp -C"
   "The preprocessor used by the cmacexp package.
 
-If you change this, be sure to preserve the -C (don't strip comments)
+If you change this, be sure to preserve the `-C' (don't strip comments)
 option, or to set an equivalent one.")
 
 (defvar c-macro-cppflags ""
-  "*Preprocessor flags used by c-macro-expand.")
+  "*Preprocessor flags used by `c-macro-expand'.")
 
 (defconst c-macro-buffer-name "*Macroexpansion*")
 
@@ -239,7 +239,8 @@ Optional arg DISPLAY non-nil means show messages in the echo area."
         (startlinenum 0)
         (linenum 0)
         (startstat ())
-        (startmarker ""))
+        (startmarker "")
+        (tempname (make-temp-name "/tmp/")))
     (unwind-protect
         (save-excursion
           (save-restriction
@@ -300,10 +301,10 @@ Optional arg DISPLAY non-nil means show messages in the echo area."
 
           ;; Call the preprocessor.
           (if display (message mymsg))
-          (call-process-region 1 (point-max) "sh" t t nil "-c"
-                               (concat cppcommand " 2>/dev/null"))
+          (setq exit-status
+                (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))
@@ -317,6 +318,16 @@ Optional arg DISPLAY non-nil means show messages in the echo area."
               (forward-line 1)
               (delete-region beg (point))))
 
+          ;; If CPP got errors, show them at the beginning.
+          (or (eq exit-status 0)
+              (progn
+                (goto-char (point-min))
+                (insert (format "Preprocessor terminated with status %s\n"
+                                exit-status))
+                (insert-file-contents tempname)
+                (insert "\n")))
+          (delete-file tempname)
+
           ;; Compute the return value, keeping in account the space
           ;; inserted at the end of the buffer.
           (buffer-substring 1 (max 1 (- (point-max) 1))))