(Autoload): Document `generate-autoload-cookie' and `generated-autoload-file'.

doc/lispref/ChangeLog

+2008-12-27  Eli Zaretskii  <eliz@gnu.org>
+
+	* loading.texi (Autoload): Document `generate-autoload-cookie' and
+	`generated-autoload-file'.
+
 2008-12-20  Eli Zaretskii  <eliz@gnu.org>
 
 	* os.texi (Startup Summary): Add xref to documentation of

doc/lispref/loading.texi

@@ -501,6 +501,9 @@ consists of @samp{;;;###autoload}, on a line by itself,
 just before the real definition of the function in its
 autoloadable source file.  The command @kbd{M-x update-file-autoloads}
 writes a corresponding @code{autoload} call into @file{loaddefs.el}.
+(The string that serves as the autoload cookie and the name of the
+file generated by @code{update-file-autoloads} can be changed from the
+above defaults, see below.)
 Building Emacs loads @file{loaddefs.el} and thus calls @code{autoload}.
 @kbd{M-x update-directory-autoloads} is even more powerful; it updates
 autoloads for all files in the current directory.
@@ -567,6 +570,26 @@ ordinary magic autoload comment would copy the whole definition into
   ...)
 @end smallexample
 
+  You can use a non-default string as the autoload cookie and have the
+corresponding autoload calls written into a file whose name is
+different from the default @file{loaddefs.el}.  Emacs provides two
+variables to control this:
+
+@defvar generate-autoload-cookie
+The value of this variable should be a string whose syntax is a Lisp
+comment.  @kbd{M-x update-file-autoloads} copies the Lisp form that
+follows the cookie into the autoload file it generates.  The default
+value of this variable is @code{";;;###autoload"}.
+@end defvar
+
+@defvar generated-autoload-file
+The value of this variable names an Emacs Lisp file where the autoload
+calls should go.  The default value is @file{loaddefs.el}, but you can
+override that, e.g., in the ``Local Variables'' section of a
+@file{.el} file (@pxref{File Local Variables}).  The autoload file is
+assumed to contain a trailer starting with a formfeed character.
+@end defvar
+
 @node Repeated Loading
 @section Repeated Loading
 @cindex repeated loading

etc/NEWS

@@ -1188,6 +1188,14 @@ functions and variables (formerly used for Tamil script).
 
 ** New coding system alias `emacs-internal'.
 
++++
+** The new variable `generate-autoload-cookie' controls the magic comment
+string used by `update-file-autoloads' to find autoloaded forms.  The
+variable `generated-autoload-file' similarly controls the name of the
+file where `update-file-autoloads' writes the calls to `autoload'.
+The default values are ";;;###autoload" and `loaddefs.el',
+respectively.
+
 +++
 ** New primitives `list-system-processes' and `system-process-attributes'
 let Lisp programs access the processes that are running on the local