(eval-when-compile (require 'cl))
(defun feature-symbols (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
(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."
(if (not (featurep 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."
(let ((symbols (assoc file load-history)))
(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 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 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))
(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.
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 &optional loaded-p)
"Read feature name from the minibuffer, prompting with string PROMPT.
If optional second arg LOADED-P is non-nil, the feature must be loaded
from a file."
(intern
(completing-read prompt
(cons nil features)
(and loaded-p
#'(lambda (f)
(and f (feature-file f))))
loaded-p)))
(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.")
(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 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 "Unload feature: " t)
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))
restore-autoload
(unload-hook (intern-soft (concat (symbol-name feature)
"-unload-hook"))))
(if unload-hook
(run-hooks unload-hook)
(mapatoms
(lambda (x)
(when (and (boundp x)
(or (and (consp (symbol-value x)) (string-match "-hooks?\\'" (symbol-name x)))
(memq x unload-feature-special-hooks))) (dolist (y unload-hook-features-list)
(when (and (eq (car-safe y) 'defun)
(not (get (cdr y) 'autoload)))
(remove-hook x (cdr y)))))))
(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) (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)
(provide
(setq features (delq (cdr x) features)))
((defun autoload)
(let ((fun (cdr x)))
(when (fboundp fun)
(when (fboundp 'ad-unadvise)
(ad-unadvise fun))
(let ((aload (get fun 'autoload)))
(if (and aload (eq fun restore-autoload))
(fset fun (cons 'autoload aload))
(fmakunbound fun))))))
((t) (setq restore-autoload (cdr x)))
((require defface) nil)
(t (message "Unexpected element %s in load-history" x)))
(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)))
(unless (local-variable-if-set-p x)
(makunbound x))))
(setq load-history (delq (assoc file load-history) load-history)))
nil)
(provide 'loadhist)