+ (macroexp--expand-all form)))
+
+;;; Handy functions to use in macros.
+
+(defun macroexp-progn (exps)
+ "Return an expression equivalent to `(progn ,@EXPS)."
+ (if (cdr exps) `(progn ,@exps) (car exps)))
+
+(defun macroexp-unprogn (exp)
+ "Turn EXP into a list of expressions to execute in sequence."
+ (if (eq (car-safe exp) 'progn) (cdr exp) (list exp)))
+
+(defun macroexp-let* (bindings exp)
+ "Return an expression equivalent to `(let* ,bindings ,exp)."
+ (cond
+ ((null bindings) exp)
+ ((eq 'let* (car-safe exp)) `(let* (,@bindings ,@(cadr exp)) ,@(cddr exp)))
+ (t `(let* ,bindings ,exp))))
+
+(defun macroexp-if (test then else)
+ "Return an expression equivalent to `(if ,test ,then ,else)."
+ (cond
+ ((eq (car-safe else) 'if)
+ (if (equal test (nth 1 else))
+ ;; Doing a test a second time: get rid of the redundancy.
+ `(if ,test ,then ,@(nthcdr 3 else))
+ `(cond (,test ,then)
+ (,(nth 1 else) ,(nth 2 else))
+ (t ,@(nthcdr 3 else)))))
+ ((eq (car-safe else) 'cond)
+ `(cond (,test ,then)
+ ;; Doing a test a second time: get rid of the redundancy, as above.
+ ,@(remove (assoc test else) (cdr else))))
+ ;; Invert the test if that lets us reduce the depth of the tree.
+ ((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)
+ "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.
+TEST should be the name of a predicate on EXP checking whether the `let' can
+be skipped; if nil, as is usual, `macroexp-const-p' is used."
+ (declare (indent 3) (debug (sexp sexp form body)))
+ (let ((bodysym (make-symbol "body"))
+ (expsym (make-symbol "exp")))
+ `(let* ((,expsym ,exp)
+ (,var (if (funcall #',(or test #'macroexp-const-p) ,expsym)
+ ,expsym (make-symbol ,(symbol-name var))))
+ (,bodysym ,(macroexp-progn exps)))
+ (if (eq ,var ,expsym) ,bodysym
+ (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
+symbol itself."
+ (or (memq symbol '(nil t))
+ (keywordp symbol)
+ (if any-value
+ (or (memq symbol byte-compile-const-variables)
+ ;; FIXME: We should provide a less intrusive way to find out
+ ;; if a variable is "constant".
+ (and (boundp symbol)
+ (condition-case nil
+ (progn (set symbol (symbol-value symbol)) nil)
+ (setting-constant t)))))))
+
+(defun macroexp-const-p (exp)
+ "Return non-nil if EXP will always evaluate to the same value."
+ (cond ((consp exp) (or (eq (car exp) 'quote)
+ (and (eq (car exp) 'function)
+ (symbolp (cadr exp)))))
+ ;; It would sometimes make sense to pass `any-value', but it's not
+ ;; always safe since a "constant" variable may not actually always have
+ ;; the same value.
+ ((symbolp exp) (macroexp--const-symbol-p exp))
+ (t t)))
+
+(defun macroexp-copyable-p (exp)
+ "Return non-nil if EXP can be copied without extra cost."
+ (or (symbolp exp) (macroexp-const-p exp)))
+
+;;; Load-time macro-expansion.
+
+;; Because macro-expansion used to be more lazy, eager macro-expansion
+;; tends to bump into previously harmless/unnoticeable cyclic-dependencies.
+;; So, we have to delay macro-expansion like we used to when we detect
+;; such a cycle, and we also want to help coders resolve those cycles (since
+;; they can be non-obvious) by providing a usefully trimmed backtrace
+;; (hopefully) highlighting the problem.
+
+(defun macroexp--backtrace ()
+ "Return the Elisp backtrace, more recent frames first."
+ (let ((bt ())
+ (i 0))
+ (while
+ (let ((frame (backtrace-frame i)))
+ (when frame
+ (push frame bt)
+ (setq i (1+ i)))))
+ (nreverse bt)))
+
+(defun macroexp--trim-backtrace-frame (frame)
+ (pcase frame
+ (`(,_ macroexpand (,head . ,_) . ,_) `(macroexpand (,head …)))
+ (`(,_ internal-macroexpand-for-load (,head ,second . ,_) . ,_)
+ (if (or (symbolp second)
+ (and (eq 'quote (car-safe second))
+ (symbolp (cadr second))))
+ `(macroexpand-all (,head ,second …))
+ '(macroexpand-all …)))
+ (`(,_ load-with-code-conversion ,name . ,_)
+ `(load ,(file-name-nondirectory name)))))
+
+(defvar macroexp--pending-eager-loads nil
+ "Stack of files currently undergoing eager macro-expansion.")
+
+(defun internal-macroexpand-for-load (form)
+ ;; Called from the eager-macroexpansion in readevalloop.
+ (cond
+ ;; Don't repeat the same warning for every top-level element.
+ ((eq 'skip (car macroexp--pending-eager-loads)) form)
+ ;; If we detect a cycle, skip macro-expansion for now, and output a warning
+ ;; with a trimmed backtrace.
+ ((and load-file-name (member load-file-name macroexp--pending-eager-loads))
+ (let* ((bt (delq nil
+ (mapcar #'macroexp--trim-backtrace-frame
+ (macroexp--backtrace))))
+ (elem `(load ,(file-name-nondirectory load-file-name)))
+ (tail (member elem (cdr (member elem bt)))))
+ (if tail (setcdr tail (list '…)))
+ (if (eq (car-safe (car bt)) 'macroexpand-all) (setq bt (cdr bt)))
+ (message "Warning: Eager macro-expansion skipped due to cycle:\n %s"
+ (mapconcat #'prin1-to-string (nreverse bt) " => "))
+ (push 'skip macroexp--pending-eager-loads)
+ form))
+ (t
+ (condition-case err
+ (let ((macroexp--pending-eager-loads
+ (cons load-file-name macroexp--pending-eager-loads)))
+ (macroexpand-all form))
+ (error
+ ;; Hopefully this shouldn't happen thanks to the cycle detection,
+ ;; but in case it does happen, let's catch the error and give the
+ ;; code a chance to macro-expand later.
+ (message "Eager macro-expansion failure: %S" err)
+ form)))))
+
+;; ¡¡¡ Big Ugly Hack !!!
+;; src/bootstrap-emacs is mostly used to compile .el files, so it needs
+;; macroexp, bytecomp, cconv, and byte-opt to be fast. Generally this is done
+;; by compiling those files first, but this only makes a difference if those
+;; files are not preloaded. But macroexp.el is preloaded so we reload it if
+;; the current version is interpreted and there's a compiled version available.
+(eval-when-compile
+ (add-hook 'emacs-startup-hook
+ (lambda ()
+ (and (not (byte-code-function-p
+ (symbol-function 'macroexpand-all)))
+ (locate-library "macroexp.elc")
+ (load "macroexp.elc")))))