Rename configure.in to configure.ac.

Fixes: debbugs:11603

26 files changed, 87 insertions, 45 deletions

diff --git a/ChangeLog b/ChangeLog
index b883a4e000a..f776e339149 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2012-07-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Rename configure.in to configure.ac (Bug#11603).
+        The name 'configure.in' has been obsolescent for quite some time,
+        and the next release of Autoconf will generate warnings for it.
+        * configure.ac: Rename from configure.in.
+        * INSTALL, INSTALL.BZR, README, make-dist:
+        * Makefile.in (AUTOCONF_INPUTS):
+        * autogen.sh (autoconf_min):
+        * autogen/update_autogen (sources):
+        Adjust to reflect new name.
+
 2012-07-08  Paul Eggert  <eggert@cs.ucla.edu>
 
         Restore deprecation warnings, except for older libpng.
diff --git a/INSTALL b/INSTALL
index 5c6bc0b97dd..2eab03975f9 100644
--- a/INSTALL
+++ b/INSTALL
@@ -683,9 +683,9 @@ changing the s/*.h and m/*.h files.
 corresponding `Makefile.in' files.  This isn't so hard, just a matter
 of editing in appropriate substitutions for the @...@ constructs.
 
-The `configure' script is built from `configure.in' by the `autoconf'
+The `configure' script is built from `configure.ac' by the `autoconf'
 program.  You need at least the version of autoconf specified in the
-AC_PREREQ(...) command to rebuild `configure' from `configure.in'.
+AC_PREREQ(...) command to rebuild `configure' from `configure.ac'.
 
 BUILDING GNU EMACS BY HAND
 
diff --git a/INSTALL.BZR b/INSTALL.BZR
index 675eaaf12df..e98d742fb33 100644
--- a/INSTALL.BZR
+++ b/INSTALL.BZR
@@ -8,7 +8,7 @@ Building Emacs from Bazaar requires some tools that are not needed
 when building from a release.  You will need:
 
 autoconf  - at least the version specified near the start of
-  configure.in (in the AC_PREREQ command).
+  configure.ac (in the AC_PREREQ command).
 automake  - we recommend at least version 1.11.
 makeinfo  - not strictly necessary, but highly recommended, so that
   you can build the manuals.
diff --git a/Makefile.in b/Makefile.in
index 0900bd1946f..95b0931087f 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -281,7 +281,7 @@ all: ${SUBDIR}
 removenullpaths=sed -e 's/^://g' -e 's/:$$//g' -e 's/::/:/g'
 
 # Generate epaths.h from epaths.in.  This target is invoked by `configure'.
-# See comments in configure.in for why it is done this way, as opposed
+# See comments in configure.ac for why it is done this way, as opposed
 # to just letting configure generate epaths.h from epaths.in in a
 # similar way to how Makefile is made from Makefile.in.
 epaths-force: FRC
@@ -364,7 +364,7 @@ config.status: ${srcdir}/configure ${srcdir}/lisp/version.el
             ./configure $(CONFIGURE_FLAGS); \
         fi
 
-AUTOCONF_INPUTS = $(srcdir)/configure.in $(srcdir)/aclocal.m4
+AUTOCONF_INPUTS = $(srcdir)/configure.ac $(srcdir)/aclocal.m4
 
 $(srcdir)/configure: $(AUTOCONF_INPUTS)
         cd ${srcdir} && autoconf
diff --git a/README b/README
index 4e1a4c4556f..de4ee24fc5e 100644
--- a/README
+++ b/README
@@ -37,12 +37,12 @@ oddities of your processor and operating system.  It creates the file
 process of building and installing Emacs.  See INSTALL for more
 detailed information.
 
-The file `configure.in' is the input used by the autoconf program to
+The file `configure.ac' is the input used by the autoconf program to
 construct the `configure' script.  Since Emacs has some configuration
 requirements that autoconf can't meet directly, and for historical
-reasons, `configure.in' uses an unholy marriage of custom-baked
+reasons, `configure.ac' uses an unholy marriage of custom-baked
 configuration code and autoconf macros.  If you want to rebuild
-`configure' from `configure.in', you will need to install a recent
+`configure' from `configure.ac', you will need to install a recent
 version of autoconf and GNU m4.
 
 The file `Makefile.in' is a template used by `configure' to create
diff --git a/admin/ChangeLog b/admin/ChangeLog
index 53b6143c82c..5ae49cd4b7a 100644
--- a/admin/ChangeLog
+++ b/admin/ChangeLog
@@ -1,3 +1,10 @@
+2012-07-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Rename configure.in to configure.ac (Bug#11603).
+        * admin.el (set-version):
+        * quick-install-emacs (VERSION):
+        Get version number from configure.ac, not configure.in.
+
 2012-07-06  Paul Eggert  <eggert@cs.ucla.edu>
 
         Use c_strcasecmp for ASCII case-insensitive comparison (Bug#11786).
diff --git a/admin/admin.el b/admin/admin.el
index 9fcc5795d21..6d729214bd0 100644
--- a/admin/admin.el
+++ b/admin/admin.el
@@ -62,7 +62,7 @@ Root must be the root of an Emacs source tree."
   (set-version-in-file root "README" version
                        (rx (and "version" (1+ space)
                                 (submatch (1+ (in "0-9."))))))
-  (set-version-in-file root "configure.in" version
+  (set-version-in-file root "configure.ac" version
                        (rx (and "AC_INIT" (1+ (not (in ?,)))
                                 ?, (0+ space)
                                 (submatch (1+ (in "0-9."))))))
diff --git a/admin/quick-install-emacs b/admin/quick-install-emacs
index 7004e8f1b27..4abef102dc4 100755
--- a/admin/quick-install-emacs
+++ b/admin/quick-install-emacs
@@ -171,9 +171,9 @@ test x"$prefix" = x && { prefix="`get_config_var prefix`" || exit 4 ; }
 test x"$ARCH" = x && { ARCH="`get_config_var host`" || exit 4 ; }
 
 VERSION=`
-  sed -n 's/^AC_INIT(emacs,[     ]*\([^  )]*\).*/\1/p' <$SRC/configure.in
+  sed -n 's/^AC_INIT(emacs,[     ]*\([^  )]*\).*/\1/p' <$SRC/configure.ac
 ` || exit 4
-test -n "$VERSION" || { echo >&2 "$me: no version in configure.in"; exit 4; }
+test -n "$VERSION" || { echo >&2 "$me: no version in configure.ac"; exit 4; }
 
 DST_SHARE="$prefix/share/emacs/$VERSION"
 DST_BIN="$prefix/bin"
diff --git a/autogen.sh b/autogen.sh
index fb5917fbbf7..0c92047e469 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -34,7 +34,7 @@
 progs="autoconf automake"
 
 ## Minimum versions we need:
-autoconf_min=`sed -n 's/^ *AC_PREREQ(\([0-9\.]*\)).*/\1/p' configure.in`
+autoconf_min=`sed -n 's/^ *AC_PREREQ(\([0-9\.]*\)).*/\1/p' configure.ac`
 
 ## FIXME how to determine this from the sources?
 automake_min=1.11
diff --git a/autogen/copy_autogen b/autogen/copy_autogen
index c9f04ad6253..b6af9b6eb35 100755
--- a/autogen/copy_autogen
+++ b/autogen/copy_autogen
@@ -3,7 +3,7 @@
 ## Helper script for those building Emacs from bzr without autoconf etc.
 ## This installs some pre-generated versions of the automatically
 ## generated files.  It is highly recommended to install the necessary
-## tools instead of using this.  Note that if eg configure.in
+## tools instead of using this.  Note that if eg configure.ac
 ## is updated, the next time you run make it will attempt to
 ## regenerate configure and will fail if you do not have the required
 ## tools.  You will have to run this script again.
diff --git a/autogen/update_autogen b/autogen/update_autogen
index 58e3838f8c1..14a4119087e 100755
--- a/autogen/update_autogen
+++ b/autogen/update_autogen
@@ -79,7 +79,7 @@ lboot_flag=
 ## Parameters.
 ldefs_in=lisp/loaddefs.el
 ldefs_out=lisp/ldefs-boot.el
-sources="configure.in lib/Makefile.am"
+sources="configure.ac lib/Makefile.am"
 genfiles="
   configure aclocal.m4 src/config.in lib/Makefile.in
   build-aux/compile build-aux/config.guess build-aux/config.sub
diff --git a/configure.in b/configure.ac
index 4df12844b1d..e4371970012 100644
--- a/configure.in
+++ b/configure.ac
@@ -3820,5 +3820,3 @@ fi
 ])
 
 AC_OUTPUT
-
-dnl configure.in ends here
diff --git a/doc/misc/ChangeLog b/doc/misc/ChangeLog
index 99e5b5d9345..d9ddc3c972b 100644
--- a/doc/misc/ChangeLog
+++ b/doc/misc/ChangeLog
@@ -1,3 +1,9 @@
+2012-07-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Rename configure.in to configure.ac (Bug#11603).
+        * ede.texi (Compiler and Linker objects, ede-proj-project)
+        (ede-step-project): Prefer the name configure.ac to configure.in.
+
 2012-07-06  Michael Albinus  <michael.albinus@gmx.de>
 
         * tramp.texi (Multi-hops): Introduce
diff --git a/doc/misc/ede.texi b/doc/misc/ede.texi
index f7e39b6c65c..655d11b5d17 100644
--- a/doc/misc/ede.texi
+++ b/doc/misc/ede.texi
@@ -790,7 +790,7 @@ compilers that will be inserted into the Makefile.
 
 Compiler instantiations must also insert variables specifying the
 compiler it plans to use, in addition to creating Automake settings for
-@file{configure.in} when appropriate.
+@file{configure.ac} when appropriate.
 
 Compiler objects are stored in the target objects as a list of
 symbols, where the symbols value is the object.  This enables the
@@ -1557,7 +1557,7 @@ For project @var{THIS}, test that the file @var{FILE} exists, or create it.
 
 @deffn Method ede-proj-setup-buildenvironment :AFTER this &optional force
 Setup the build environment for project @var{THIS}.
-Handles the Makefile, or a Makefile.am configure.in combination.
+Handles the Makefile, or a Makefile.am configure.ac combination.
 Optional argument @var{FORCE} will force items to be regenerated.
 @end deffn
 
@@ -1567,7 +1567,7 @@ These are removed with make clean.
 @end deffn
 
 @deffn Method ede-proj-configure-synchronize :AFTER this
-Synchronize what we know about project @var{THIS} into configure.in.
+Synchronize what we know about project @var{THIS} into configure.ac.
 @end deffn
 
 @deffn Method ede-proj-makefile-insert-variables-new :AFTER this
@@ -1603,7 +1603,7 @@ Return the name of the Makefile with the DIST target in it for @var{THIS}.
 @end deffn
 
 @deffn Method ede-proj-configure-file :AFTER this
-The configure.in script used by project @var{THIS}.
+The configure.ac script used by project @var{THIS}.
 @end deffn
 
 @deffn Method ede-commit-project :AFTER proj
@@ -1767,7 +1767,7 @@ Create a Makefile for all Makefile targets in @var{THIS} if needed.
 
 @deffn Method ede-proj-setup-buildenvironment :AFTER this &optional force
 Setup the build environment for project @var{THIS}.
-Handles the Makefile, or a Makefile.am configure.in combination.
+Handles the Makefile, or a Makefile.am configure.ac combination.
 Optional argument @var{FORCE} will force items to be regenerated.
 @end deffn
 
diff --git a/etc/future-bug b/etc/future-bug
index fb6262dfe55..c18dd995d66 100644
--- a/etc/future-bug
+++ b/etc/future-bug
@@ -30,7 +30,7 @@ comments when you write it (sometime in 2198 as I recall).
 
 
 P.S. You'll be pleased to know that since (time-forward N) still works
-     for N >= 0, we've used it to pre-emptively update configure.in.
+     for N >= 0, we've used it to pre-emptively update configure.ac.
      Emacs now configures and builds on every platform that will ever
      be made.  It wasn't easy, but at least that's one problem out of
      the way for good.  If you'd like the patch, just ask.
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index dbe37763d7a..d5d676ec7d5 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2012-07-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Rename configure.in to configure.ac (Bug#11603).
+        * emacs-lisp/authors.el (authors-canonical-file-name):
+        * progmodes/autoconf.el (autoconf-mode):
+        Prefer configure.ac to configure.in.
+
 2012-07-08  Chong Yidong  <cyd@gnu.org>
 
         * mouse.el (mouse-drag-line): Rewrite the track-mouse loop.
diff --git a/lisp/cedet/ChangeLog b/lisp/cedet/ChangeLog
index f185c457ee2..bbf700311e1 100644
--- a/lisp/cedet/ChangeLog
+++ b/lisp/cedet/ChangeLog
@@ -1,3 +1,13 @@
+2012-07-09  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Rename configure.in to configure.ac (Bug#11603).
+        * ede/autoconf-edit.el (autoconf-find-query-for-program)
+        (autoconf-new-program):
+        * ede/emacs.el (ede-emacs-version):
+        * ede/proj.el (ede-proj-setup-buildenvironment):
+        * ede/project-am.el (project-am-autoconf-file-options):
+        Prefer configure.ac to configure.in.
+
 2012-03-12  David Engster  <deng@randomsample.de>
 
         * semantic/db-find.el
diff --git a/lisp/cedet/ede/autoconf-edit.el b/lisp/cedet/ede/autoconf-edit.el
index 666ba0b0a06..e3c9d2cb4f8 100644
--- a/lisp/cedet/ede/autoconf-edit.el
+++ b/lisp/cedet/ede/autoconf-edit.el
@@ -31,7 +31,7 @@
 (declare-function ede-srecode-insert "ede/srecode")
 
 (defun autoconf-new-program (rootdir program testfile)
-  "Initialize a new configure.in in ROOTDIR for PROGRAM using TESTFILE.
+  "Initialize a new configure.ac in ROOTDIR for PROGRAM using TESTFILE.
 ROOTDIR is the root directory of a given autoconf controlled project.
 PROGRAM is the program to be configured.
 TESTFILE is the file used with AC_INIT.
@@ -325,7 +325,7 @@ Optional argument PARAM is the parameter to pass to the macro as one string."
   "Position the cursor where PROG is queried.
 PROG is the VARIABLE to use in autoconf to identify the program.
 PROG excludes the _PROG suffix.  Thus if PROG were EMACS, then the
-variable in configure.in would be EMACS_PROG."
+variable in configure.ac would be EMACS_PROG."
   (let ((op (point))
         (found t)
         (builtin (assoc prog autoconf-program-builtin)))
diff --git a/lisp/cedet/ede/emacs.el b/lisp/cedet/ede/emacs.el
index d7c83749ffa..e3afe30063c 100644
--- a/lisp/cedet/ede/emacs.el
+++ b/lisp/cedet/ede/emacs.el
@@ -74,13 +74,16 @@ DIR is the directory to search from."
   "Find the Emacs version for the Emacs src in DIR.
 Return a tuple of ( EMACSNAME . VERSION )."
   (let ((buff (get-buffer-create " *emacs-query*"))
+        (configure_ac "configure.ac")
         (emacs "Emacs")
         (ver ""))
     (with-current-buffer buff
       (erase-buffer)
       (setq default-directory (file-name-as-directory dir))
+      (or (file-exists-p configure_ac)
+          (setq configure_ac "configure.in"))
       ;(call-process "egrep" nil buff nil "-n" "-e" "^version=" "Makefile")
-      (call-process "egrep" nil buff nil "-n" "-e" "AC_INIT" "configure.in")
+      (call-process "egrep" nil buff nil "-n" "-e" "AC_INIT" configure_ac)
       (goto-char (point-min))
       ;(re-search-forward "version=\\([0-9.]+\\)")
       (cond
@@ -100,7 +103,7 @@ emacs_beta_version=\\([0-9]+\\)")
 
        ;; Vaguely recent version of GNU Emacs?
        (t
-        (insert-file-contents "configure.in")
+        (insert-file-contents configure_ac)
         (goto-char (point-min))
         (re-search-forward "AC_INIT(emacs,\\s-*\\([0-9.]+\\)\\s-*)")
         (setq ver (match-string 1))
diff --git a/lisp/cedet/ede/proj.el b/lisp/cedet/ede/proj.el
index d80d55bf916..a8afe9ec804 100644
--- a/lisp/cedet/ede/proj.el
+++ b/lisp/cedet/ede/proj.el
@@ -642,7 +642,7 @@ MFILENAME is the makefile to generate."
 (defmethod ede-proj-setup-buildenvironment ((this ede-proj-project)
                                             &optional force)
   "Setup the build environment for project THIS.
-Handles the Makefile, or a Makefile.am configure.in combination.
+Handles the Makefile, or a Makefile.am configure.ac combination.
 Optional argument FORCE will force items to be regenerated."
   (if (not force)
       (ede-proj-makefile-create-maybe this (ede-proj-dist-makefile this))
diff --git a/lisp/cedet/ede/project-am.el b/lisp/cedet/ede/project-am.el
index b775cddbc0e..1caaee4b7d4 100644
--- a/lisp/cedet/ede/project-am.el
+++ b/lisp/cedet/ede/project-am.el
@@ -896,10 +896,10 @@ files in the project."
     out))
 
 
-;;; Configure.in queries.
+;;; Configure.am queries.
 ;;
 (defvar project-am-autoconf-file-options
-  '("configure.in" "configure.ac")
+  '("configure.ac" "configure.in")
   "List of possible configure files to look in for project info.")
 
 (defun project-am-autoconf-file (dir)
@@ -948,7 +948,7 @@ Kill the Configure buffer if it was not already in a buffer."
         (configfiles nil)
         )
     (cond
-     ;; Try configure.in or configure.ac
+     ;; Try configure.ac or configure.in
      (conf-in
       (project-am-with-config-current conf-in
         (let ((aci (autoconf-parameters-for-macro "AC_INIT"))
diff --git a/lisp/emacs-lisp/authors.el b/lisp/emacs-lisp/authors.el
index babb5bf8fc9..aa1a7b52f4c 100644
--- a/lisp/emacs-lisp/authors.el
+++ b/lisp/emacs-lisp/authors.el
@@ -702,7 +702,7 @@ or is on the list of removed files.  Returns the non-directory part of
 the file name.  Only uses the LOG-FILE position POS and associated AUTHOR
 to print a message if FILE is not found."
   ;; FILE should be re-checked in every different directory associated
-  ;; with a LOG-FILE.  Eg configure.in from src/ChangeLog is not the
+  ;; with a LOG-FILE.  Eg configure.ac from src/ChangeLog is not the
   ;; same as that from top-level/ChangeLog.
   (let* ((fullname (expand-file-name file (file-name-directory log-file)))
          (entry (assoc fullname authors-checked-files-alist))
diff --git a/lisp/info-look.el b/lisp/info-look.el
index 5eca62ed1bd..eb780fe5620 100644
--- a/lisp/info-look.el
+++ b/lisp/info-look.el
@@ -732,7 +732,7 @@ Return nil if there is nothing appropriate in the buffer near point."
  :parse-rule "\\$[^({]\\|\\.[_A-Z]*\\|[_a-zA-Z0-9-]+\\|##\\|\\+="
  :doc-spec   '(
                ;; "(automake)Macro Index" is autoconf macros used in
-               ;; configure.in, not Makefile.am, so don't have that here.
+               ;; configure.ac, not Makefile.am, so don't have that here.
                ("(automake)Variable Index" nil "^[ \t]*`" "'")
                ;; In automake 1.4 macros and variables were a combined node.
                ("(automake)Macro and Variable Index" nil "^[ \t]*`" "'")
diff --git a/lisp/progmodes/autoconf.el b/lisp/progmodes/autoconf.el
index a7242f6c232..3225fef2dfa 100644
--- a/lisp/progmodes/autoconf.el
+++ b/lisp/progmodes/autoconf.el
@@ -1,4 +1,4 @@
-;;; autoconf.el --- mode for editing Autoconf configure.in files
+;;; autoconf.el --- mode for editing Autoconf configure.ac files
 
 ;; Copyright (C) 2000-2012  Free Software Foundation, Inc.
 
@@ -23,15 +23,15 @@
 ;;; Commentary:
 
 ;; Provides fairly minimal font-lock, imenu and indentation support
-;; for editing configure.in files.  Only Autoconf syntax is processed.
+;; for editing configure.ac files.  Only Autoconf syntax is processed.
 ;; There is no attempt to deal with shell text -- probably that will
 ;; always lose.
 
-;; This is specialized for configure.in files.  It doesn't inherit the
+;; This is specialized for configure.ac files.  It doesn't inherit the
 ;; general M4 stuff from M4 mode.
 
 ;; There is also an autoconf-mode.el in existence.  That appears to be
-;; for editing the Autoconf M4 source, rather than configure.in files.
+;; for editing the Autoconf M4 source, rather than configure.ac files.
 
 ;;; Code:
 
@@ -49,7 +49,7 @@
   `(("\\_<A[CHMS]_\\sw+" . font-lock-keyword-face)
     (,autoconf-definition-regexp
      3 font-lock-function-name-face)
-    ;; Are any other M4 keywords really appropriate for configure.in,
+    ;; Are any other M4 keywords really appropriate for configure.ac,
     ;; given that we do `dnl'?
     ("changequote" . font-lock-keyword-face)))
 
@@ -78,7 +78,7 @@ searching backwards at another AC_... command."
 
 ;;;###autoload
 (define-derived-mode autoconf-mode prog-mode "Autoconf"
-  "Major mode for editing Autoconf configure.in files."
+  "Major mode for editing Autoconf configure.ac files."
   (set (make-local-variable 'parens-require-spaces) nil) ; for M4 arg lists
   (set (make-local-variable 'defun-prompt-regexp)
        "^[ \t]*A[CM]_\\(\\sw\\|\\s_\\)+")
diff --git a/make-dist b/make-dist
index 0582f994672..cc14ff3987b 100755
--- a/make-dist
+++ b/make-dist
@@ -147,7 +147,7 @@ fi
 
 ### Find out which version of Emacs this is.
 version=`
-  sed -n 's/^AC_INIT(emacs,[     ]*\([^  )]*\).*/\1/p' <configure.in
+  sed -n 's/^AC_INIT(emacs,[     ]*\([^  )]*\).*/\1/p' <configure.ac
 ` || version=
 if [ ! "${version}" ]; then
   echo "${progname}: can't find current Emacs version in \`./src/emacs.c'" >&2
@@ -230,13 +230,13 @@ fi
 
 if [ $update = yes ]; then
 
-  ## Make sure configure is newer than configure.in, etc.
+  ## Make sure configure is newer than configure.ac, etc.
   ## It is better to let autoreconf do what is needed than
   ## for us to try and duplicate all its checks.
   echo "Running autoreconf"
   autoreconf -i -I m4 || { x=$?; echo Autoreconf FAILED! >&2; exit $x; }
 
-  ## Make sure src/stamp-h.in is newer than configure.in.
+  ## Make sure src/stamp-h.in is newer than configure.ac.
   rm -f src/stamp-h.in
   echo timestamp > src/stamp-h.in
 
@@ -273,7 +273,7 @@ mkdir ${tempdir}
 ### README while the rest of the tar file is still unpacking.  Whoopee.
 echo "Making links to top-level files"
 ln INSTALL README BUGS ${tempdir}
-ln ChangeLog Makefile.in configure configure.in ${tempdir}
+ln ChangeLog Makefile.in configure configure.ac ${tempdir}
 ln config.bat make-dist .dir-locals.el ${tempdir}
 ln aclocal.m4 ${tempdir}
 
diff --git a/src/s/template.h b/src/s/template.h
index e3557aa191b..17c003a8df5 100644
--- a/src/s/template.h
+++ b/src/s/template.h
@@ -94,14 +94,13 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* ============================================================ */
 
 /* After adding support for a new system, modify the large case
-   statement in configure.in to recognize reasonable
+   statement in configure.ac to recognize reasonable
    configuration names, and add a description of the system to
    `etc/MACHINES'.
 
-   Check for any tests of $opsys in configure.in, and add an entry
+   Check for any tests of $opsys in configure.ac, and add an entry
    for the new system if needed.
 
    If you've just fixed a problem in an existing configuration file,
    you should also check `etc/MACHINES' to make sure its descriptions
    of known problems in that configuration should be updated.  */
-