1 ;;; disass.el --- disassembler for compiled Emacs Lisp code
3 ;;; Copyright (C) 1986, 1991-1994 Free Software Foundation, Inc.
5 ;; Author: Doug Cutting <doug@csli.stanford.edu>
6 ;; Jamie Zawinski <jwz@jwz.org>
7 ;; Maintainer: XEmacs Development Team
10 ;; This file is part of XEmacs.
12 ;; XEmacs is free software; you can redistribute it and/or modify it
13 ;; under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation; either version 2, or (at your option)
17 ;; XEmacs is distributed in the hope that it will be useful, but
18 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 ;; General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with XEmacs; see the file COPYING. If not, write to the
24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25 ;; Boston, MA 02111-1307, USA.
27 ;;; Synched up with: FSF 19.28.
31 ;; The single entry point, `disassemble', disassembles a code object generated
32 ;; by the Emacs Lisp byte-compiler. This doesn't invert the compilation
33 ;; operation, not by a long shot, but it's useful for debugging.
36 ;; Original version by Doug Cutting (doug@csli.stanford.edu)
37 ;; Substantially modified by Jamie Zawinski for
38 ;; the new lapcode-based byte compiler.
42 (require 'byte-optimize)
44 (defvar disassemble-column-1-indent 8 "*")
45 (defvar disassemble-column-2-indent 10 "*")
46 (defvar disassemble-recursive-indent 3 "*")
49 (defun disassemble (object &optional buffer indent interactive-p)
50 "Print disassembled code for OBJECT in (optional) BUFFER.
51 OBJECT can be a symbol defined as a function, or a function itself
52 \(a lambda expression or a compiled-function object).
53 If OBJECT is not already compiled, we compile it, but do not
54 redefine OBJECT if it is a symbol."
55 (interactive (list (intern (completing-read "Disassemble function: "
58 (if (eq (car-safe object) 'byte-code)
59 (setq object (list 'lambda () object)))
60 (or indent (setq indent 0)) ;Default indent to zero
62 (if (or interactive-p (null buffer))
63 (with-output-to-temp-buffer "*Disassemble*"
64 (set-buffer "*Disassemble*")
65 (disassemble-internal object indent (not interactive-p)))
67 (disassemble-internal object indent nil)))
71 (defun disassemble-internal (obj indent interactive-p)
77 obj (symbol-function obj)))
79 (error "Can't disassemble #<subr %s>" name))
80 (if (eq (car-safe obj) 'autoload)
83 (setq obj (symbol-function name))))
84 (if (eq (car-safe obj) 'macro) ;handle macros
87 (if (and (listp obj) (eq (car obj) 'byte-code))
88 (setq obj (list 'lambda nil obj)))
89 (if (and (listp obj) (not (eq (car obj) 'lambda)))
90 (error "not a function"))
92 (if (assq 'byte-code obj)
94 (if interactive-p (message (if name
95 "Compiling %s's definition..."
96 "Compiling definition...")
98 (setq obj (byte-compile obj))
99 (if interactive-p (message "Done compiling. Disassembling..."))))
101 (setq obj (cdr obj)) ;throw lambda away
102 (setq args (car obj)) ;save arg list
103 (setq obj (cdr obj)))
105 (setq args (compiled-function-arglist obj))))
106 (if (zerop indent) ; not a nested function
109 (insert (format "byte code%s%s%s:\n"
110 (if (or macro name) " for" "")
111 (if macro " macro" "")
112 (if name (format " %s" name) "")))))
113 (let ((doc (if (consp obj)
114 (and (stringp (car obj)) (car obj))
115 (condition-case error
117 (error (format "%S" error))))))
118 (if (and doc (stringp doc))
119 (progn (and (consp obj) (setq obj (cdr obj)))
121 (princ " doc: " (current-buffer))
123 (if (string-match "\n" doc)
124 (setq doc (substring doc 0 (match-beginning 0))
126 (if (> (length doc) 70)
127 (setq doc (substring doc 0 65) frobbed t))
128 (if frobbed (setq doc (concat doc " ..."))))
132 (prin1 args (current-buffer))
134 (if (condition-case ()
135 (commandp obj) ; ie interactivep
137 (let ((interactive (if (consp obj)
138 (elt (assq 'interactive obj) 1)
139 (elt (compiled-function-interactive obj) 1))))
140 (if (eq (car-safe (car-safe obj)) 'interactive)
141 (setq obj (cdr obj)))
143 (insert " interactive: ")
144 (if (eq (car-safe interactive) 'byte-code)
147 (disassemble-1 interactive
148 (+ indent disassemble-recursive-indent)))
149 (let ((print-escape-newlines t))
150 (prin1 interactive (current-buffer))))
152 (cond ((and (consp obj) (assq 'byte-code obj))
153 (disassemble-1 (assq 'byte-code obj) indent))
154 ((compiled-function-p obj)
155 (disassemble-1 obj indent))
157 (insert "Uncompiled body: ")
158 (let ((print-escape-newlines t))
159 (prin1 (if (cdr obj) (cons 'progn obj) (car obj))
160 (current-buffer))))))
165 (defun disassemble-1 (obj indent)
166 "Print the byte-code call OBJ in the current buffer.
167 OBJ should be a compiled-function object generated by the byte compiler."
168 (let (bytes constvec)
170 (setq bytes (car (cdr obj)) ; the byte code
171 constvec (car (cdr (cdr obj)))) ; constant vector
172 (setq bytes (compiled-function-instructions obj)
173 constvec (compiled-function-constants obj)))
174 (let ((lap (byte-decompile-bytecode bytes constvec))
175 op arg opname pc-value)
179 (while (setq tmp (assq 'TAG lap))
180 (setcar (cdr tmp) (setq tagno (1+ tagno)))
181 (setq lap (cdr (memq tmp lap)))))
183 ;; Take off the pc value of the next thing
184 ;; and put it in pc-value.
186 (if (numberp (car lap))
187 (setq pc-value (car lap)
189 ;; Fetch the next op and its arg.
190 (setq op (car (car lap))
196 ;; We have a label. Display it, but first its pc value.
198 (insert (format "%d:" pc-value)))
199 (insert (int-to-string (car arg))))
200 ;; We have an instruction. Display its pc value first.
202 (insert (format "%d" pc-value)))
203 (indent-to (+ indent disassemble-column-1-indent))
205 (string-match "^byte-" (setq opname (symbol-name op))))
206 (setq opname (substring opname 5))
207 (setq opname "<not-an-opcode>"))
208 (if (eq op 'byte-constant2)
209 (insert " #### shouldn't have seen constant2 here!\n "))
211 (indent-to (+ indent disassemble-column-1-indent
212 disassemble-column-2-indent
215 (cond ((memq op byte-goto-ops)
216 (insert (int-to-string (nth 1 arg))))
217 ((memq op '(byte-call byte-unbind
218 byte-listN byte-concatN byte-insertN))
219 (insert (int-to-string arg)))
220 ((memq op '(byte-varref byte-varset byte-varbind))
221 (prin1 (car arg) (current-buffer)))
222 ((memq op '(byte-constant byte-constant2))
225 ;; but if the value of the constant is compiled code, then
226 ;; recursively disassemble it.
227 (cond ((or (compiled-function-p arg)
228 (and (eq (car-safe arg) 'lambda)
229 (assq 'byte-code arg))
230 (and (eq (car-safe arg) 'macro)
231 (or (compiled-function-p (cdr arg))
232 (and (eq (car-safe (cdr arg)) 'lambda)
233 (assq 'byte-code (cdr arg))))))
234 (cond ((compiled-function-p arg)
235 (insert "<compiled-function>\n"))
236 ((eq (car-safe arg) 'lambda)
237 (insert "<compiled lambda>"))
238 (t (insert "<compiled macro>\n")))
239 (disassemble-internal
241 (+ indent disassemble-recursive-indent 1)
243 ((eq (car-safe arg) 'byte-code)
244 (insert "<byte code>\n")
245 (disassemble-1 ;recurse on byte-code object
247 (+ indent disassemble-recursive-indent)))
248 ((eq (car-safe (car-safe arg)) 'byte-code)
249 (insert "(<byte code>...)\n")
250 (mapcar ;recurse on list of byte-code objects
254 (+ indent disassemble-recursive-indent)))
257 ;; really just a constant
258 (let ((print-escape-newlines t))
259 (prin1 arg (current-buffer))))))
266 ;;; disass.el ends here