1 ;;; disass.el --- disassembler for compiled Emacs Lisp code
3 ;; Copyright (C) 1986, 1991, 2002, 2003, 2004,
4 ;; 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
6 ;; Author: Doug Cutting <doug@csli.stanford.edu>
7 ;; Jamie Zawinski <jwz@lucid.com>
11 ;; This file is part of GNU Emacs.
13 ;; GNU Emacs is free software: you can redistribute it and/or modify
14 ;; it under the terms of the GNU General Public License as published by
15 ;; the Free Software Foundation, either version 3 of the License, or
16 ;; (at your option) any later version.
18 ;; GNU Emacs is distributed in the hope that it will be useful,
19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ;; GNU General Public License for more details.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
28 ;; The single entry point, `disassemble', disassembles a code object generated
29 ;; by the Emacs Lisp byte-compiler. This doesn't invert the compilation
30 ;; operation, not by a long shot, but it's useful for debugging.
33 ;; Original version by Doug Cutting (doug@csli.stanford.edu)
34 ;; Substantially modified by Jamie Zawinski <jwz@lucid.com> for
35 ;; the new lapcode-based byte compiler.
39 ;;; The variable byte-code-vector is defined by the new bytecomp.el.
40 ;;; The function byte-decompile-lapcode is defined in byte-opt.el.
41 ;;; Since we don't use byte-decompile-lapcode, let's try not loading byte-opt.
42 (require 'byte-compile
"bytecomp")
44 (defvar disassemble-column-1-indent
8 "*")
45 (defvar disassemble-column-2-indent
10 "*")
47 (defvar disassemble-recursive-indent
3 "*")
50 (defun disassemble (object &optional buffer indent interactive-p
)
51 "Print disassembled code for OBJECT in (optional) BUFFER.
52 OBJECT can be a symbol defined as a function, or a function itself
53 \(a lambda expression or a compiled-function object).
54 If OBJECT is not already compiled, we compile it, but do not
55 redefine OBJECT if it is a symbol."
56 (interactive (list (intern (completing-read "Disassemble function: "
59 (if (and (consp object
) (not (eq (car object
) 'lambda
)))
60 (setq object
(list 'lambda
() object
)))
61 (or indent
(setq indent
0)) ;Default indent to zero
63 (if (or interactive-p
(null buffer
))
64 (with-output-to-temp-buffer "*Disassemble*"
65 (set-buffer "*Disassemble*")
66 (disassemble-internal object indent
(not interactive-p
)))
68 (disassemble-internal object indent nil
)))
72 (defun disassemble-internal (obj indent interactive-p
)
80 obj
(symbol-function obj
)))
82 (error "Can't disassemble #<subr %s>" name
))
83 (when (and (listp obj
) (eq (car obj
) 'autoload
))
85 (setq obj
(symbol-function name
)))
86 (if (eq (car-safe obj
) 'macro
) ;handle macros
89 (when (and (listp obj
) (eq (car obj
) 'closure
))
90 (setq lexical-binding t
)
91 (setq obj
(cddr obj
)))
92 (if (and (listp obj
) (eq (car obj
) 'byte-code
))
93 (setq obj
(list 'lambda nil obj
)))
94 (if (and (listp obj
) (not (eq (car obj
) 'lambda
)))
95 (error "not a function"))
97 (if (assq 'byte-code obj
)
99 (if interactive-p
(message (if name
100 "Compiling %s's definition..."
101 "Compiling definition...")
103 (setq obj
(byte-compile obj
))
104 (if interactive-p
(message "Done compiling. Disassembling..."))))
106 (setq obj
(cdr obj
)) ;throw lambda away
107 (setq args
(car obj
)) ;save arg list
108 (setq obj
(cdr obj
)))
109 ((byte-code-function-p obj
)
110 (setq args
(aref obj
0)))
111 (t (error "Compilation failed")))
112 (if (zerop indent
) ; not a nested function
115 (insert (format "byte code%s%s%s:\n"
116 (if (or macro name
) " for" "")
117 (if macro
" macro" "")
118 (if name
(format " %s" name
) "")))))
119 (let ((doc (if (consp obj
)
120 (and (stringp (car obj
)) (car obj
))
121 ;; Use documentation to get lazy-loaded doc string
122 (documentation obj t
))))
123 (if (and doc
(stringp doc
))
124 (progn (and (consp obj
) (setq obj
(cdr obj
)))
126 (princ " doc: " (current-buffer))
127 (if (string-match "\n" doc
)
128 (setq doc
(concat (substring doc
0 (match-beginning 0))
133 (prin1 args
(current-buffer))
135 (let ((interactive (cond ((consp obj
)
136 (assq 'interactive obj
))
138 (list 'interactive
(aref obj
5))))))
141 (setq interactive
(nth 1 interactive
))
142 (if (eq (car-safe (car-safe obj
)) 'interactive
)
143 (setq obj
(cdr obj
)))
145 (insert " interactive: ")
146 (if (eq (car-safe interactive
) 'byte-code
)
149 (disassemble-1 interactive
150 (+ indent disassemble-recursive-indent
)))
151 (let ((print-escape-newlines t
))
152 (prin1 interactive
(current-buffer))))
154 (cond ((and (consp obj
) (assq 'byte-code obj
))
155 (disassemble-1 (assq 'byte-code obj
) indent
))
156 ((byte-code-function-p obj
)
157 (disassemble-1 obj indent
))
159 (insert "Uncompiled body: ")
160 (let ((print-escape-newlines t
))
161 (prin1 (if (cdr obj
) (cons 'progn obj
) (car obj
))
162 (current-buffer))))))
167 (defun disassemble-1 (obj indent
)
168 "Prints the byte-code call OBJ in the current buffer.
169 OBJ should be a call to BYTE-CODE generated by the byte compiler."
170 (let (bytes constvec
)
172 (setq bytes
(car (cdr obj
)) ;the byte code
173 constvec
(car (cdr (cdr obj
)))) ;constant vector
174 ;; If it is lazy-loaded, load it now
176 (setq bytes
(aref obj
1)
177 constvec
(aref obj
2)))
178 (let ((lap (byte-decompile-bytecode (string-as-unibyte bytes
) constvec
))
179 op arg opname pc-value
)
183 (while (setq tmp
(assq 'TAG lap
))
184 (setcar (cdr tmp
) (setq tagno
(1+ tagno
)))
185 (setq lap
(cdr (memq tmp lap
)))))
187 ;; Take off the pc value of the next thing
188 ;; and put it in pc-value.
190 (if (numberp (car lap
))
191 (setq pc-value
(car lap
)
193 ;; Fetch the next op and its arg.
194 (setq op
(car (car lap
))
200 ;; We have a label. Display it, but first its pc value.
202 (insert (format "%d:" pc-value
)))
203 (insert (int-to-string (car arg
))))
204 ;; We have an instruction. Display its pc value first.
206 (insert (format "%d" pc-value
)))
207 (indent-to (+ indent disassemble-column-1-indent
))
209 (string-match "^byte-" (setq opname
(symbol-name op
))))
210 (setq opname
(substring opname
5))
211 (setq opname
"<not-an-opcode>"))
212 (if (eq op
'byte-constant2
)
213 (insert " #### shouldn't have seen constant2 here!\n "))
215 (indent-to (+ indent disassemble-column-1-indent
216 disassemble-column-2-indent
219 (cond ((memq op byte-goto-ops
)
220 (insert (int-to-string (nth 1 arg
))))
221 ((memq op
'(byte-call byte-unbind
222 byte-listN byte-concatN byte-insertN
223 byte-stack-ref byte-stack-set byte-stack-set2
224 byte-discardN byte-discardN-preserve-tos
))
225 (insert (int-to-string arg
)))
226 ((memq op
'(byte-varref byte-varset byte-varbind
))
227 (prin1 (car arg
) (current-buffer)))
228 ((memq op
'(byte-constant byte-constant2
))
231 ;; but if the value of the constant is compiled code, then
232 ;; recursively disassemble it.
233 (cond ((or (byte-code-function-p arg
)
234 (and (eq (car-safe arg
) 'lambda
)
235 (assq 'byte-code arg
))
236 (and (eq (car-safe arg
) 'macro
)
237 (or (byte-code-function-p (cdr arg
))
238 (and (eq (car-safe (cdr arg
)) 'lambda
)
239 (assq 'byte-code
(cdr arg
))))))
240 (cond ((byte-code-function-p arg
)
241 (insert "<compiled-function>\n"))
242 ((eq (car-safe arg
) 'lambda
)
243 (insert "<compiled lambda>"))
244 (t (insert "<compiled macro>\n")))
245 (disassemble-internal
247 (+ indent disassemble-recursive-indent
1)
249 ((eq (car-safe arg
) 'byte-code
)
250 (insert "<byte code>\n")
251 (disassemble-1 ;recurse on byte-code object
253 (+ indent disassemble-recursive-indent
)))
254 ((eq (car-safe (car-safe arg
)) 'byte-code
)
255 (insert "(<byte code>...)\n")
256 (mapc ;recurse on list of byte-code objects
260 (+ indent disassemble-recursive-indent
)))
263 ;; really just a constant
264 (let ((print-escape-newlines t
))
265 (prin1 arg
(current-buffer))))))
272 ;; arch-tag: 89482fe4-a087-4761-8dc6-d771054e763a
273 ;;; disass.el ends here