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, 22 insertions, 1 deletions

diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el
index 95fe43a34a2..6275fd1cdf8 100644
--- a/lisp/emacs-lisp/macroexp.el
+++ b/lisp/emacs-lisp/macroexp.el
@@ -263,7 +263,7 @@ definitions to shadow the loaded ones for use in file byte-compilation."
    ((memq (car-safe then) '(if cond)) (macroexp-if `(not ,test) else then))
    (t `(if ,test ,then ,else))))
 
-(defmacro macroexp-let² (test var exp &rest exps)
+(defmacro macroexp-let2 (test var exp &rest exps)
   "Bind VAR to a copyable expression that returns the value of EXP.
 This is like `(let ((v ,EXP)) ,EXPS) except that `v' is a new generated
 symbol which EXPS can find in VAR.
@@ -280,6 +280,27 @@ be skipped; if nil, as is usual, `macroexp-const-p' is used."
          (macroexp-let* (list (list ,var ,expsym))
                         ,bodysym)))))
 
+(defun macroexp--maxsize (exp size)
+  (cond ((< size 0) size)
+        ((symbolp exp) (1- size))
+        ((stringp exp) (- size (/ (length exp) 16)))
+        ((vectorp exp)
+         (dotimes (i (length exp))
+           (setq size (macroexp--maxsize (aref exp i) size)))
+         (1- size))
+        ((consp exp)
+         ;; We could try to be more clever with quote&function,
+         ;; but it is difficult to do so correctly, and it's not obvious that
+         ;; it would be worth the effort.
+         (dolist (e exp)
+           (setq size (macroexp--maxsize e size)))
+         (1- size))
+        (t -1)))
+
+(defun macroexp-small-p (exp)
+  "Return non-nil if EXP can be considered small."
+  (> (macroexp--maxsize exp 10) 0))
+
 (defsubst macroexp--const-symbol-p (symbol &optional any-value)
   "Non-nil if SYMBOL is constant.
 If ANY-VALUE is nil, only return non-nil if the value of the symbol is the