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2b86d62c | 1 | ;;; loadhist.el --- lisp functions for working with feature groups |
b578f267 | 2 | |
fde4581d | 3 | ;; Copyright (C) 1995, 1998 Free Software Foundation, Inc. |
2b86d62c RS |
4 | |
5 | ;; Author: Eric S. Raymond <esr@snark.thyrsus.com> | |
6 | ;; Version: 1.0 | |
7 | ;; Keywords: internal | |
8 | ||
131a0c01 KH |
9 | ;; This file is part of GNU Emacs. |
10 | ||
11 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
12 | ;; it under the terms of the GNU General Public License as published by | |
13 | ;; the Free Software Foundation; either version 2, or (at your option) | |
14 | ;; any later version. | |
15 | ||
16 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
17 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | ;; GNU General Public License for more details. | |
20 | ||
21 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
22 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
23 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
24 | ;; Boston, MA 02111-1307, USA. | |
131a0c01 | 25 | |
2b86d62c RS |
26 | ;;; Commentary: |
27 | ||
28 | ;; These functions exploit the load-history system variable. | |
fde4581d RS |
29 | ;; Entry points include `unload-feature', `symbol-file', and |
30 | ;; `feature-file', documented in the Emacs Lisp manual. | |
2b86d62c RS |
31 | |
32 | ;;; Code: | |
33 | ||
2b86d62c RS |
34 | (defun feature-symbols (feature) |
35 | "Return the file and list of symbols associated with a given FEATURE." | |
36 | (catch 'foundit | |
37 | (mapcar | |
38 | (function (lambda (x) | |
39 | (if (member (cons 'provide feature) (cdr x)) | |
40 | (throw 'foundit x)))) | |
41 | load-history) | |
42 | nil)) | |
43 | ||
44 | (defun feature-file (feature) | |
45 | "Return the file name from which a given FEATURE was loaded. | |
46 | Actually, return the load argument, if any; this is sometimes the name of a | |
47 | Lisp file without an extension. If the feature came from an eval-buffer on | |
48 | a buffer with no associated file, or an eval-region, return nil." | |
49 | (if (not (featurep feature)) | |
a5c31fa1 | 50 | (error "%s is not a currently loaded feature" (symbol-name feature)) |
2b86d62c RS |
51 | (car (feature-symbols feature)))) |
52 | ||
53 | (defun file-provides (file) | |
54 | "Return the list of features provided by FILE." | |
55 | (let ((symbols (cdr (assoc file load-history))) (provides nil)) | |
56 | (mapcar | |
57 | (function (lambda (x) | |
58 | (if (and (consp x) (eq (car x) 'provide)) | |
59 | (setq provides (cons (cdr x) provides))))) | |
60 | symbols) | |
61 | provides | |
62 | )) | |
63 | ||
64 | (defun file-requires (file) | |
65 | "Return the list of features required by FILE." | |
66 | (let ((symbols (cdr (assoc file load-history))) (requires nil)) | |
67 | (mapcar | |
68 | (function (lambda (x) | |
69 | (if (and (consp x) (eq (car x) 'require)) | |
70 | (setq requires (cons (cdr x) requires))))) | |
71 | symbols) | |
72 | requires | |
73 | )) | |
74 | ||
a5c31fa1 | 75 | (defun file-set-intersect (p q) |
2b86d62c RS |
76 | ;; Return the set intersection of two lists |
77 | (let ((ret nil)) | |
78 | (mapcar | |
79 | (function (lambda (x) (if (memq x q) (setq ret (cons x ret))))) | |
80 | p) | |
81 | ret | |
82 | )) | |
83 | ||
84 | (defun file-dependents (file) | |
e01ac82c RS |
85 | "Return the list of loaded libraries that depend on FILE. |
86 | This can include FILE itself." | |
2b86d62c RS |
87 | (let ((provides (file-provides file)) (dependents nil)) |
88 | (mapcar | |
89 | (function (lambda (x) | |
a5c31fa1 | 90 | (if (file-set-intersect provides (file-requires (car x))) |
2b86d62c RS |
91 | (setq dependents (cons (car x) dependents))))) |
92 | load-history) | |
93 | dependents | |
94 | )) | |
95 | ||
d4708676 | 96 | (defun read-feature (prompt) |
fde4581d RS |
97 | "Read a feature name \(string\) from the minibuffer. |
98 | Prompt with PROMPT and completing from `features', and | |
d4708676 RS |
99 | return the feature \(symbol\)." |
100 | (intern (completing-read prompt | |
101 | (mapcar (function (lambda (feature) | |
102 | (list (symbol-name feature)))) | |
103 | features) | |
104 | nil t))) | |
105 | ||
fde4581d RS |
106 | (defvar loadhist-hook-functions |
107 | '(after-change-function after-change-functions | |
108 | after-insert-file-functions auto-fill-function before-change-function | |
109 | before-change-functions blink-paren-function | |
110 | buffer-access-fontify-functions command-line-functions | |
111 | comment-indent-function kill-buffer-query-functions | |
112 | kill-emacs-query-functions lisp-indent-function | |
113 | redisplay-end-trigger-functions temp-buffer-show-function | |
114 | window-scroll-functions window-size-change-functions | |
115 | write-region-annotate-functions) | |
116 | "A list of special hooks from the `Standard Hooks' node of the Lisp manual. | |
117 | ||
118 | These are symbols with hook-type values whose names don't end in | |
119 | `-hook' or `-hooks', from which `unload-feature' tries to remove | |
120 | pertinent symbols.") | |
121 | ||
2b86d62c RS |
122 | ;;;###autoload |
123 | (defun unload-feature (feature &optional force) | |
124 | "Unload the library that provided FEATURE, restoring all its autoloads. | |
125 | If the feature is required by any other loaded code, and optional FORCE | |
126 | is nil, raise an error." | |
d4708676 | 127 | (interactive (list (read-feature "Feature: "))) |
2b86d62c | 128 | (if (not (featurep feature)) |
a5c31fa1 | 129 | (error "%s is not a currently loaded feature" (symbol-name feature))) |
2b86d62c | 130 | (if (not force) |
e01ac82c RS |
131 | (let* ((file (feature-file feature)) |
132 | (dependents (delete file (copy-sequence (file-dependents file))))) | |
2b86d62c | 133 | (if dependents |
a5c31fa1 | 134 | (error "Loaded libraries %s depend on %s" |
fde4581d RS |
135 | (prin1-to-string dependents) file)))) |
136 | (let* ((flist (feature-symbols feature)) | |
137 | (file (car flist)) | |
138 | (unload-hook (intern-soft (concat (symbol-name feature) | |
139 | "-unload-hook")))) | |
140 | ;; Try to avoid losing badly when hooks installed in critical | |
141 | ;; places go away. (Some packages install things on | |
142 | ;; `kill-buffer-hook', `activate-menubar-hook' and the like.) | |
143 | ;; First off, provide a clean way for package `foo' to arrange | |
144 | ;; this by defining `foo-unload-hook'. | |
145 | (if unload-hook | |
146 | (run-hooks unload-hook) | |
147 | ;; Otherwise, do our best. Look through the obarray for symbols | |
148 | ;; which seem to be hook variables or special hook functions and | |
149 | ;; remove anything from them which matches the feature-symbols | |
150 | ;; about to get zapped. Obviously this won't get anonymous | |
151 | ;; functions which the package might just have installed, and | |
152 | ;; there might be other important state, but this tactic | |
153 | ;; normally works. | |
154 | (mapatoms | |
155 | (lambda (x) | |
156 | (if (or (and (boundp x) ; Random hooks. | |
157 | (consp (symbol-value x)) | |
158 | (string-match "-hooks?\\'" (symbol-name x))) | |
159 | (and (fboundp x) ; Known abnormal hooks etc. | |
160 | (memq x loadhist-hook-functions))) | |
161 | (mapcar (lambda (y) (remove-hook x y)) | |
162 | (cdr flist)))))) | |
2b86d62c | 163 | (mapcar |
fde4581d RS |
164 | (lambda (x) |
165 | (cond ((stringp x) nil) | |
166 | ((consp x) | |
167 | ;; Remove any feature names that this file provided. | |
168 | (if (eq (car x) 'provide) | |
169 | (setq features (delq (cdr x) features)))) | |
170 | ((boundp x) (makunbound x)) | |
171 | ((fboundp x) | |
172 | (fmakunbound x) | |
173 | (let ((aload (get x 'autoload))) | |
174 | (if aload (fset x (cons 'autoload aload))))))) | |
a5c31fa1 RS |
175 | (cdr flist)) |
176 | ;; Delete the load-history element for this file. | |
177 | (let ((elt (assoc file load-history))) | |
178 | (setq load-history (delq elt load-history))))) | |
2b86d62c RS |
179 | |
180 | (provide 'loadhist) | |
181 | ||
182 | ;;; loadhist.el ends here |