+;; `flet' and `labels' got obsolete since Emacs 24.3.
+(defmacro gmm-flet (bindings &rest body)
+ "Make temporary overriding function definitions.
+
+\(fn ((FUNC ARGLIST BODY...) ...) FORM...)"
+ `(let (fn origs)
+ (dolist (bind ',bindings)
+ (setq fn (car bind))
+ (push (cons fn (and (fboundp fn) (symbol-function fn))) origs)
+ (fset fn (cons 'lambda (cdr bind))))
+ (unwind-protect
+ (progn ,@body)
+ (dolist (orig origs)
+ (if (cdr orig)
+ (fset (car orig) (cdr orig))
+ (fmakunbound (car orig)))))))
+(put 'gmm-flet 'lisp-indent-function 1)
+
+;; An alist of original function names and those unique names.
+(defvar gmm-labels-environment)
+
+(defun gmm-labels-expand (form)
+ "Expand funcalls in FORM according to `gmm-labels-environment'.
+This function is a subroutine that `gmm-labels' uses to convert any
+`(FN ...)' and #'FN elements in FORM into `(funcall UN ...)' and `UN'
+respectively if `(FN . UN)' is listed in `gmm-labels-environment'."
+ (cond ((or (not (consp form)) (memq (car form) '(\` backquote quote)))
+ form)
+ ((assq (car form) gmm-labels-environment)
+ `(funcall ,(cdr (assq (car form) gmm-labels-environment))
+ ,@(mapcar #'gmm-labels-expand (cdr form))))
+ ((eq (car form) 'function)
+ (if (and (assq (cadr form) gmm-labels-environment)
+ (not (cddr form)))
+ (cdr (assq (cadr form) gmm-labels-environment))
+ (cons 'function (mapcar #'gmm-labels-expand (cdr form)))))
+ (t
+ (mapcar #'gmm-labels-expand form))))
+
+(defmacro gmm-labels (bindings &rest body)
+ "Make temporary function bindings.
+The lexical scoping is handled via `lexical-let' rather than relying
+on `lexical-binding'.
+
+\(fn ((FUNC ARGLIST BODY...) ...) FORM...)"
+ (let (gmm-labels-environment def defs)
+ (dolist (binding bindings)
+ (push (cons (car binding)
+ (make-symbol (format "--gmm-%s--" (car binding))))
+ gmm-labels-environment))
+ `(lexical-let ,(mapcar #'cdr gmm-labels-environment)
+ (setq ,@(dolist (env gmm-labels-environment (nreverse defs))
+ (setq def (cdr (assq (car env) bindings)))
+ (push (cdr env) defs)
+ (push `(lambda ,(car def)
+ ,@(mapcar #'gmm-labels-expand (cdr def)))
+ defs)))
+ ,@(mapcar #'gmm-labels-expand body))))
+(put 'gmm-labels 'lisp-indent-function 1)
+