;;; loadhist.el --- lisp functions for working with feature groups
-;; Copyright (C) 1995 Free Software Foundation, Inc.
+;; Copyright (C) 1995, 1998, 2000, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
-;; Version: 1.0
+;; Maintainer: FSF
;; Keywords: internal
;; This file is part of GNU Emacs.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; These functions exploit the load-history system variable.
-;; Entry points include `unload-feature', `symbol-file', and `feature-file'.
+;; Entry points include `unload-feature', `symbol-file', and
+;; `feature-file', documented in the Emacs Lisp manual.
;;; Code:
-(defun symbol-file (sym)
- "Return the input source from which SYM was loaded.
-This is a file name, or nil if the source was a buffer with no associated file."
- (catch 'foundit
- (mapcar
- (function (lambda (x) (if (memq sym (cdr x)) (throw 'foundit (car x)))))
- load-history)
- nil))
+(eval-when-compile (require 'cl))
(defun feature-symbols (feature)
- "Return the file and list of symbols associated with a given FEATURE."
+ "Return the file and list of definitions associated with FEATURE.
+The value is actually the element of `load-history'
+for the file that did (provide FEATURE)."
(catch 'foundit
- (mapcar
- (function (lambda (x)
- (if (member (cons 'provide feature) (cdr x))
- (throw 'foundit x))))
- load-history)
+ (mapc (lambda (x)
+ (if (member (cons 'provide feature) (cdr x))
+ (throw 'foundit x)))
+ load-history)
nil))
(defun feature-file (feature)
"Return the file name from which a given FEATURE was loaded.
Actually, return the load argument, if any; this is sometimes the name of a
-Lisp file without an extension. If the feature came from an eval-buffer on
-a buffer with no associated file, or an eval-region, return nil."
+Lisp file without an extension. If the feature came from an `eval-buffer' on
+a buffer with no associated file, or an `eval-region', return nil."
(if (not (featurep feature))
- (error "%s is not a currently loaded feature" (symbol-name feature))
+ (error "%S is not a currently loaded feature" feature)
(car (feature-symbols feature))))
+(defun file-loadhist-lookup (file)
+ "Return the `load-history' element for FILE.
+FILE can be a file name, or a library name.
+A library name is equivalent to the file name that `load-library' would load."
+ ;; First look for FILE as given.
+ (let ((symbols (assoc file load-history)))
+ ;; Try converting a library name to an absolute file name.
+ (and (null symbols)
+ (let ((absname
+ (locate-file file load-path (get-load-suffixes))))
+ (and absname (not (equal absname file))
+ (setq symbols (cdr (assoc absname load-history))))))
+ symbols))
+
(defun file-provides (file)
- "Return the list of features provided by FILE."
- (let ((symbols (cdr (assoc file load-history))) (provides nil))
- (mapcar
- (function (lambda (x)
- (if (and (consp x) (eq (car x) 'provide))
- (setq provides (cons (cdr x) provides)))))
- symbols)
- provides
- ))
+ "Return the list of features provided by FILE as it was loaded.
+FILE can be a file name, or a library name.
+A library name is equivalent to the file name that `load-library' would load."
+ (let ((symbols (file-loadhist-lookup file))
+ provides)
+ (mapc (lambda (x)
+ (if (and (consp x) (eq (car x) 'provide))
+ (setq provides (cons (cdr x) provides))))
+ symbols)
+ provides))
(defun file-requires (file)
- "Return the list of features required by FILE."
- (let ((symbols (cdr (assoc file load-history))) (requires nil))
- (mapcar
- (function (lambda (x)
- (if (and (consp x) (eq (car x) 'require))
- (setq requires (cons (cdr x) requires)))))
- symbols)
- requires
- ))
-
-(defun file-set-intersect (p q)
- ;; Return the set intersection of two lists
+ "Return the list of features required by FILE as it was loaded.
+FILE can be a file name, or a library name.
+A library name is equivalent to the file name that `load-library' would load."
+ (let ((symbols (file-loadhist-lookup file))
+ requires)
+ (mapc (lambda (x)
+ (if (and (consp x) (eq (car x) 'require))
+ (setq requires (cons (cdr x) requires))))
+ symbols)
+ requires))
+
+(defsubst file-set-intersect (p q)
+ "Return the set intersection of two lists."
(let ((ret nil))
- (mapcar
- (function (lambda (x) (if (memq x q) (setq ret (cons x ret)))))
- p)
- ret
- ))
+ (dolist (x p ret)
+ (if (memq x q) (setq ret (cons x ret))))
+ ret))
(defun file-dependents (file)
"Return the list of loaded libraries that depend on FILE.
-This can include FILE itself."
- (let ((provides (file-provides file)) (dependents nil))
- (mapcar
- (function (lambda (x)
- (if (file-set-intersect provides (file-requires (car x)))
- (setq dependents (cons (car x) dependents)))))
- load-history)
- dependents
- ))
+This can include FILE itself.
+FILE can be a file name, or a library name.
+A library name is equivalent to the file name that `load-library' would load."
+ (let ((provides (file-provides file))
+ (dependents nil))
+ (dolist (x load-history dependents)
+ (if (file-set-intersect provides (file-requires (car x)))
+ (setq dependents (cons (car x) dependents))))
+ dependents))
(defun read-feature (prompt)
- "Read a feature name \(string\) from the minibuffer,
-prompting with PROMPT and completing from `features', and
+ "Read a feature name \(string\) from the minibuffer.
+Prompt with PROMPT and completing from `features', and
return the feature \(symbol\)."
(intern (completing-read prompt
- (mapcar (function (lambda (feature)
- (list (symbol-name feature))))
+ (mapcar (lambda (feature)
+ (list (symbol-name feature)))
features)
nil t)))
+(defvaralias 'loadhist-hook-functions 'unload-feature-special-hooks)
+(defvar unload-feature-special-hooks
+ '(after-change-functions
+ after-insert-file-functions auto-fill-function
+ before-change-functions blink-paren-function
+ buffer-access-fontify-functions command-line-functions
+ comment-indent-function kill-buffer-query-functions
+ kill-emacs-query-functions lisp-indent-function
+ mouse-position-function
+ redisplay-end-trigger-functions temp-buffer-show-function
+ window-scroll-functions window-size-change-functions
+ write-region-annotate-functions)
+ "A list of special hooks from Info node `(elisp)Standard Hooks'.
+
+These are symbols with hook-type values whose names don't end in
+`-hook' or `-hooks', from which `unload-feature' tries to remove
+pertinent symbols.")
+
+(defvar unload-hook-features-list nil
+ "List of features of the package being unloaded.
+
+This is meant to be used by FEATURE-unload-hook hooks, see the
+documentation of `unload-feature' for details.")
+
;;;###autoload
(defun unload-feature (feature &optional force)
"Unload the library that provided FEATURE, restoring all its autoloads.
-If the feature is required by any other loaded code, and optional FORCE
-is nil, raise an error."
- (interactive (list (read-feature "Feature: ")))
- (if (not (featurep feature))
- (error "%s is not a currently loaded feature" (symbol-name feature)))
- (if (not force)
- (let* ((file (feature-file feature))
- (dependents (delete file (copy-sequence (file-dependents file)))))
- (if dependents
- (error "Loaded libraries %s depend on %s"
- (prin1-to-string dependents) file)
- )))
- (let* ((flist (feature-symbols feature)) (file (car flist)))
- (mapcar
- (function (lambda (x)
- (cond ((stringp x) nil)
- ((consp x)
- ;; Remove any feature names that this file provided.
- (if (eq (car x) 'provide)
- (setq features (delq (cdr x) features))))
- ((boundp x) (makunbound x))
- ((fboundp x)
- (fmakunbound x)
- (let ((aload (get x 'autoload)))
- (if aload (fset x (cons 'autoload aload))))))))
- (cdr flist))
+If the feature is required by any other loaded code, and prefix arg FORCE
+is nil, raise an error.
+
+This function tries to undo modifications made by the package to
+hooks. Packages may define a hook FEATURE-unload-hook that is called
+instead of the normal heuristics for doing this. Such a hook should
+undo all the relevant global state changes that may have been made by
+loading the package or executing functions in it. It has access to
+the package's feature list (before anything is unbound) in the
+variable `unload-hook-features-list' and could remove features from it
+in the event that the package has done something normally-ill-advised,
+such as redefining an Emacs function."
+ (interactive (list (read-feature "Feature: ") current-prefix-arg))
+ (unless (featurep feature)
+ (error "%s is not a currently loaded feature" (symbol-name feature)))
+ (unless force
+ (let* ((file (feature-file feature))
+ (dependents (delete file (copy-sequence (file-dependents file)))))
+ (when dependents
+ (error "Loaded libraries %s depend on %s"
+ (prin1-to-string dependents) file))))
+ (let* ((unload-hook-features-list (feature-symbols feature))
+ (file (pop unload-hook-features-list))
+ (unload-hook (intern-soft (concat (symbol-name feature)
+ "-unload-hook"))))
+ ;; Try to avoid losing badly when hooks installed in critical
+ ;; places go away. (Some packages install things on
+ ;; `kill-buffer-hook', `activate-menubar-hook' and the like.)
+ ;; First off, provide a clean way for package FOO to arrange
+ ;; this by adding hooks on the variable `FOO-unload-hook'.
+ (if unload-hook
+ (run-hooks unload-hook)
+ ;; Otherwise, do our best. Look through the obarray for symbols
+ ;; which seem to be hook variables or special hook functions and
+ ;; remove anything from them which matches the feature-symbols
+ ;; about to get zapped. Obviously this won't get anonymous
+ ;; functions which the package might just have installed, and
+ ;; there might be other important state, but this tactic
+ ;; normally works.
+ (mapatoms
+ (lambda (x)
+ (when (and (boundp x)
+ (or (and (consp (symbol-value x)) ; Random hooks.
+ (string-match "-hooks?\\'" (symbol-name x)))
+ (memq x unload-feature-special-hooks))) ; Known abnormal hooks etc.
+ (dolist (y unload-hook-features-list)
+ (when (and (eq (car-safe y) 'defun)
+ (not (get (cdr y) 'autoload)))
+ (remove-hook x (cdr y)))))))
+ ;; Remove any feature-symbols from auto-mode-alist as well.
+ (dolist (y unload-hook-features-list)
+ (when (and (eq (car-safe y) 'defun)
+ (not (get (cdr y) 'autoload)))
+ (setq auto-mode-alist
+ (rassq-delete-all (cdr y) auto-mode-alist)))))
+ (when (fboundp 'elp-restore-function) ; remove ELP stuff first
+ (dolist (elt unload-hook-features-list)
+ (when (symbolp elt)
+ (elp-restore-function elt))))
+ (dolist (x unload-hook-features-list)
+ (if (consp x)
+ (case (car x)
+ ;; Remove any feature names that this file provided.
+ (provide
+ (setq features (delq (cdr x) features)))
+ (defun
+ (let ((fun (cdr x)))
+ (when (fboundp fun)
+ (when (fboundp 'ad-unadvise)
+ (ad-unadvise fun))
+ (let ((aload (get fun 'autoload)))
+ (if aload
+ (fset fun (cons 'autoload aload))
+ (fmakunbound fun))))))
+ (require nil)
+ (t (message "Unexpected element %s in load-history" x)))
+ ;; Kill local values as much as possible.
+ (dolist (buf (buffer-list))
+ (with-current-buffer buf
+ (if (and (boundp x) (timerp (symbol-value x)))
+ (cancel-timer (symbol-value x)))
+ (kill-local-variable x)))
+ (if (and (boundp x) (timerp (symbol-value x)))
+ (cancel-timer (symbol-value x)))
+ ;; Get rid of the default binding if we can.
+ (unless (local-variable-if-set-p x)
+ (makunbound x))))
;; Delete the load-history element for this file.
- (let ((elt (assoc file load-history)))
- (setq load-history (delq elt load-history)))))
+ (setq load-history (delq (assoc file load-history) load-history))))
(provide 'loadhist)
+;; arch-tag: 70bb846a-c413-4f01-bf88-78dba4ac0798
;;; loadhist.el ends here