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|
;;; w3-elisp.el --- Scripting support for emacs-lisp
;; Author: wmperry
;; Created: 1997/03/07 14:14:02
;; Version: 1.7
;; Keywords: hypermedia, scripting
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Copyright (c) 1997 Free Software Foundation, Inc.
;;;
;;; This file is part of GNU Emacs.
;;;
;;; GNU Emacs is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2, or (at your option)
;;; any later version.
;;;
;;; GNU Emacs is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; 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.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(require 'cl)
(mapcar
(function
(lambda (x)
(put x 'w3-safe t)))
'(;; Any safe functions for untrusted scripts should go here.
;; Basic stuff
message
format garbage-collect progn prog1 prog2 progn-with-message
while current-time current-time-string
plist-member plist-to-alist plist-get
assoc memq member function lambda point
;; Device querying
device-pixel-height device-type device-color-cells
device-mm-height device-class device-bitplanes
device-on-window-system-p device-pixel-width
device-mm-width device-baud-rate
;; Frame querying
frame-type frame-name frame-device frame-parameters
frame-height frame-pixel-width frame-pixel-height
frame-width frame-property
;; Window querying
window-frame window-height window-width
window-pixel-width window-pixel-height
;; Buffer querying
buffer-name buffer-substring buffer-substring-no-properties
buffer-size buffer-string
;; Text properties, read-only
get-text-property text-properties-at text-property-bounds
text-property-not-all
;; URL loading stuff
url-insert-file-contents url-view-url
;; Interfacing to W3
w3-fetch w3-refresh-buffer w3-view-this-url
;; All the XEmacs event manipulation functions
event-live-p event-glyph-extent event-glyph-y-pixel event-x-pixel
event-type event-glyph event-button event-over-text-area-p
event-glyph-x-pixel event-buffer event-device event-properties
event-process event-timestamp event-modifier-bits event-console
event-window-y-pixel event-window event-window-x-pixel event-point
event-function event-over-toolbar-p event-matches-key-specifier-p
event-over-glyph-p event-frame event-x event-channel event-y
event-screen event-to-character event-over-border-p
event-toolbar-button event-closest-point event-object event-key
event-modifiers event-y-pixel event-over-modeline-p
event-modeline-position
)
)
(defsubst w3-elisp-safe-function (func args)
(let ((validator (get func 'w3-safe)))
(cond
((eq t validator) t) ; Explicit allow
((eq nil validator) nil) ; Explicit deny
((fboundp validator) ; Function to call
(funcall validator func args))
((boundp validator) ; Variable to check
(symbol-value validator))
(t nil)))) ; Fallback to unsafe
(defun w3-elisp-safe-expression (exp)
"Return t if-and-only-if EXP is safe to evaluate."
(cond
((and (listp exp) (not (listp (cdr exp)))) ; A cons cell
t)
((or ; self-quoters
(vectorp exp)
(numberp exp)
(symbolp exp)
(stringp exp)
(keymapp exp))
t)
((listp exp) ; Function call - check arguments
(if (w3-elisp-safe-function (car exp) (cdr exp))
(let ((args (cdr exp))
(rval t))
(while args
(if (not (w3-elisp-safe-expression (pop args)))
(setq args nil
rval nil)))
rval)))
;; How to handle the insane # of native types?
(t nil)))
(defun w3-elisp-safe-eval (form)
(if (w3-elisp-safe-expression form)
(condition-case ()
(eval form)
(error nil))))
(provide 'w3-elisp)
|
