Provide generalized variables in core Elisp.

* lisp/emacs-lisp/gv.el: New file.
* lisp/subr.el (push, pop): Extend to generalized variables.
* lisp/loadup.el (macroexp): Unload if preloaded and uncompiled.
* lisp/emacs-lisp/cl-lib.el (cl-pop, cl-push, cl--set-nthcdr): Remove.
* lisp/emacs-lisp/cl-macs.el: Require gv.  Use gv-define-setter,
gv-define-simple-setter, and gv-define-expander.
Remove setf-methods defined in gv.  Rename cl-setf -> setf.
(cl-setf, cl-do-pop, cl-get-setf-method): Remove.
(cl-letf, cl-letf*, cl-define-modify-macro, cl-defsetf)
(cl-define-setf-expander, cl-struct-setf-expander): Move to cl.el.
(cl-remf, cl-shiftf, cl-rotatef, cl-callf, cl-callf2): Rewrite with
gv-letplace.
(cl-defstruct): Don't define setf-method any more.
* lisp/emacs-lisp/cl.el (flet): Don't autoload.
(cl--letf, letf, cl--letf*, letf*, cl--gv-adapt)
(define-setf-expander, defsetf, define-modify-macro)
(cl-struct-setf-expander): Move from cl-lib.el.
* lisp/emacs-lisp/syntax.el:
* lisp/emacs-lisp/ewoc.el:
* lisp/emacs-lisp/smie.el:
* lisp/emacs-lisp/cconv.el:
* lisp/emacs-lisp/timer.el: Rename cl-setf -> setf, cl-push -> push.
(timer--time): Use gv-define-simple-setter.
* lisp/emacs-lisp/macroexp.el (macroexp-let2): Rename from macroexp-let²
to avoid coding-system problems in subr.el.  Adjust all users.
(macroexp--maxsize, macroexp-small-p): New functions.
* lisp/emacs-lisp/bytecomp.el (byte-compile-file): Don't use cl-letf.
* lisp/scroll-bar.el (scroll-bar-mode):
* lisp/simple.el (auto-fill-mode, overwrite-mode, binary-overwrite-mode)
(normal-erase-is-backspace-mode): Don't use the `eq' place.
* lisp/winner.el (winner-configuration, winner-make-point-alist)
(winner-set-conf, winner-get-point, winner-set): Don't abuse letf.
* lisp/files.el (locate-file-completion-table): Avoid list*.

Fixes: debbugs:11657

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/emacs-lisp/cl-extra.el b/lisp/emacs-lisp/cl-extra.el
index 53c83e73d2e..e64623ab44e 100644
--- a/lisp/emacs-lisp/cl-extra.el
+++ b/lisp/emacs-lisp/cl-extra.el
@@ -305,7 +305,7 @@ If so, return the true (non-nil) value returned by PREDICATE.
 	  (setq cl-ovl (cdr cl-ovl))))
       (set-marker cl-mark nil) (if cl-mark2 (set-marker cl-mark2 nil)))))
 
-;;; Support for `cl-setf'.
+;;; Support for `setf'.
 ;;;###autoload
 (defun cl--set-frame-visible-p (frame val)
   (cond ((null val) (make-frame-invisible frame))
@@ -590,6 +590,7 @@ If START or END is negative, it counts from the end."
   (declare (compiler-macro cl--compiler-macro-get))
   (or (get sym tag)
       (and def
+           ;; Make sure `def' is really absent as opposed to set to nil.
 	   (let ((plist (symbol-plist sym)))
 	     (while (and plist (not (eq (car plist) tag)))
 	       (setq plist (cdr (cdr plist))))
@@ -607,6 +608,7 @@ PROPLIST is a list of the sort returned by `symbol-plist'.
       ;; but that fails, because cl-get has a compiler macro
       ;; definition that uses getf!
       (when def
+        ;; Make sure `def' is really absent as opposed to set to nil.
 	(while (and plist (not (eq (car plist) tag)))
 	  (setq plist (cdr (cdr plist))))
 	(if plist (car (cdr plist)) def))))