1 files changed, 13 insertions, 12 deletions

diff --git a/lisp/emacs-lisp/autoload.el b/lisp/emacs-lisp/autoload.el
index 05e1c228ea7..593cdb68284 100644
--- a/lisp/emacs-lisp/autoload.el
+++ b/lisp/emacs-lisp/autoload.el
@@ -683,18 +683,19 @@ directory or directories specified."
 (defun batch-update-autoloads ()
   "Update loaddefs.el autoloads in batch mode.
 Calls `update-directory-autoloads' on the command line arguments."
-  ;; For use during the Emacs build process only.  We do the file-name
-  ;; expansion here rather than in lisp/Makefile in order to keep the
-  ;; shell command line short.  (Long lines are an issue on some systems.)
-  (if (stringp autoload-excludes)
-      (setq autoload-excludes
-            (mapcar
-             (lambda (file)
-               (concat
-                (expand-file-name (file-name-sans-extension file)
-                                  (file-name-directory generated-autoload-file))
-                ".el"))
-             (split-string autoload-excludes))))
+  ;; For use during the Emacs build process only.
+  (unless autoload-excludes
+    (let* ((ldir (file-name-directory generated-autoload-file))
+           (mfile (expand-file-name "../src/Makefile" ldir))
+           lim)
+      (when (file-readable-p mfile)
+        (with-temp-buffer
+          (insert-file-contents mfile)
+          (when (re-search-forward "^lisp= ")
+            (setq lim (line-end-position))
+            (while (re-search-forward "\\${lispsource}\\([^ ]*\\)\\.elc?" lim t)
+              (push (concat (expand-file-name (match-string 1) ldir) ".el")
+                    autoload-excludes)))))))
   (let ((args command-line-args-left))
     (setq command-line-args-left nil)
     (apply 'update-directory-autoloads args)))