lisp/emacs-lisp/disass.el

   1 ;;; Disassembler for compiled Emacs Lisp code
   2 ;;; Copyright (C) 1986 Free Software Foundation, Inc.
   3 ;;; Original version by Doug Cutting (doug@csli.stanford.edu)
   4 ;;; Substantially modified by Jamie Zawinski <jwz@lucid.com> for
   5 ;;; the new lapcode-based byte compiler.
   6 ;;; Last modified 22-oct-91.
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 1, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24
  25 ;;; The variable byte-code-vector is defined by the new bytecomp.el.
  26 ;;; The function byte-decompile-lapcode is defined in byte-optimize.el.
  27 (require 'byte-optimize)
  28
  29 (defvar disassemble-column-1-indent 5 "*")
  30 (defvar disassemble-column-2-indent 10 "*")
  31
  32 (defvar disassemble-recursive-indent 3 "*")
  33
  34 (defun disassemble (object &optional buffer indent interactive-p)
  35   "Print disassembled code for OBJECT in (optional) BUFFER.
  36 OBJECT can be a symbol defined as a function, or a function itself
  37 \(a lambda expression or a compiled-function object).
  38 If OBJECT is not already compiled, we compile it, but do not
  39 redefine OBJECT if it is a symbol."
  40   (interactive (list (intern (completing-read "Disassemble function: "
  41                                               obarray 'fboundp t))
  42                      nil 0 t))
  43   (if (eq (car-safe object) 'byte-code)
  44       (setq object (list 'lambda () object)))
  45   (or indent (setq indent 0))           ;Default indent to zero
  46   (save-excursion
  47     (if (or interactive-p (null buffer))
  48         (with-output-to-temp-buffer "*Disassemble*"
  49           (set-buffer "*Disassemble*")
  50           (disassemble-internal object indent (not interactive-p)))
  51       (set-buffer buffer)
  52       (disassemble-internal object indent nil)))
  53   nil)
  54
  55
  56 (defun disassemble-internal (obj indent interactive-p)
  57   (let ((macro 'nil)
  58         (name 'nil)
  59         (doc 'nil)
  60         args)
  61     (while (symbolp obj)
  62       (setq name obj
  63             obj (symbol-function obj)))
  64     (if (subrp obj)
  65         (error "Can't disassemble #<subr %s>" name))
  66     (if (eq (car-safe obj) 'macro)      ;handle macros
  67         (setq macro t
  68               obj (cdr obj)))
  69     (if (and (listp obj) (not (eq (car obj) 'lambda)))
  70         (error "not a function"))
  71     (if (consp obj)
  72         (if (assq 'byte-code obj)
  73             nil
  74           (if interactive-p (message (if name
  75                                          "Compiling %s's definition..."
  76                                        "Compiling definition...")
  77                                      name))
  78           (setq obj (byte-compile obj))
  79           (if interactive-p (message "Done compiling.  Disassembling..."))))
  80     (cond ((consp obj)
  81            (setq obj (cdr obj))         ;throw lambda away
  82            (setq args (car obj))        ;save arg list
  83            (setq obj (cdr obj)))
  84           (t
  85            (setq args (aref obj 0))))
  86     (if (zerop indent) ; not a nested function
  87         (progn
  88           (indent-to indent)
  89           (insert (format "byte code%s%s%s:\n"
  90                           (if (or macro name) " for" "")
  91                           (if macro " macro" "")
  92                           (if name (format " %s" name) "")))))
  93     (let ((doc (if (consp obj)
  94                    (and (stringp (car obj)) (car obj))
  95                  (and (> (length obj) 4) (aref obj 4)))))
  96       (if (and doc (stringp doc))
  97           (progn (and (consp obj) (setq obj (cdr obj)))
  98                  (indent-to indent)
  99                  (princ "  doc:  " (current-buffer))
 100                  (if (string-match "\n" doc)
 101                      (setq doc (concat (substring doc 0 (match-beginning 0))
 102                                        " ...")))
 103                  (insert doc "\n"))))
 104     (indent-to indent)
 105     (insert "  args: ")
 106     (prin1 args (current-buffer))
 107     (insert "\n")
 108     (let ((interactive (cond ((consp obj)
 109                               (assq 'interactive obj))
 110                              ((> (length obj) 5)
 111                               (list 'interactive (aref obj 5))))))
 112       (if interactive
 113           (progn
 114             (setq interactive (nth 1 interactive))
 115             (if (eq (car-safe (car-safe obj)) 'interactive)
 116                 (setq obj (cdr obj)))
 117             (indent-to indent)
 118             (insert " interactive: ")
 119             (if (eq (car-safe interactive) 'byte-code)
 120                 (progn
 121                   (insert "\n")
 122                   (disassemble-1 interactive
 123                                  (+ indent disassemble-recursive-indent)))
 124               (let ((print-escape-newlines t))
 125                 (prin1 interactive (current-buffer))))
 126             (insert "\n"))))
 127     (cond ((and (consp obj) (assq 'byte-code obj))
 128            (disassemble-1 (assq 'byte-code obj) indent))
 129           ((compiled-function-p obj)
 130            (disassemble-1 obj indent))
 131           (t
 132            (insert "Uncompiled body:  ")
 133            (let ((print-escape-newlines t))
 134              (prin1 (if (cdr obj) (cons 'progn obj) (car obj))
 135                     (current-buffer))))))
 136   (if interactive-p
 137       (message "")))
 138
 139
 140 (defun disassemble-1 (obj indent)
 141   "Prints the byte-code call OBJ in the current buffer.
 142 OBJ should be a call to BYTE-CODE generated by the byte compiler."
 143   (let (bytes constvec)
 144     (if (consp obj)
 145         (setq bytes (car (cdr obj))             ;the byte code
 146               constvec (car (cdr (cdr obj))))   ;constant vector
 147       (setq bytes (aref obj 1)
 148             constvec (aref obj 2)))
 149     (let ((lap (byte-decompile-bytecode bytes constvec))
 150           op arg opname)
 151       (let ((tagno 0)
 152             tmp
 153             (lap lap))
 154         (while (setq tmp (assq 'TAG lap))
 155           (setcar (cdr tmp) (setq tagno (1+ tagno)))
 156           (setq lap (cdr (memq tmp lap)))))
 157       (while lap
 158         (setq op (car (car lap))
 159               arg (cdr (car lap)))
 160         (indent-to indent)
 161         (if (eq 'TAG op)
 162             (insert (int-to-string (car arg)) ":")
 163
 164           (indent-to (+ indent disassemble-column-1-indent))
 165           (if (and op
 166                    (string-match "^byte-" (setq opname (symbol-name op))))
 167               (setq opname (substring opname 5))
 168             (setq opname "<not-an-opcode>"))
 169           (if (eq op 'byte-constant2)
 170               (insert " #### shouldn't have seen constant2 here!\n  "))
 171           (insert opname)
 172           (indent-to (+ indent disassemble-column-1-indent
 173                         disassemble-column-2-indent
 174                         -1))
 175           (insert " ")
 176           (cond ((memq op byte-goto-ops)
 177                  (insert (int-to-string (nth 1 arg))))
 178                 ((memq op '(byte-call byte-unbind
 179                             byte-listN byte-concatN byte-insertN))
 180                  (insert (int-to-string arg)))
 181                 ((memq op '(byte-varref byte-varset byte-varbind))
 182                  (prin1 (car arg) (current-buffer)))
 183                 ((memq op '(byte-constant byte-constant2))
 184                  ;; it's a constant
 185                  (setq arg (car arg))
 186                  ;; but if the value of the constant is compiled code, then
 187                  ;; recursively disassemble it.
 188                  (cond ((or (compiled-function-p arg)
 189                             (and (eq (car-safe arg) 'lambda)
 190                                  (assq 'byte-code arg))
 191                             (and (eq (car-safe arg) 'macro)
 192                                  (or (compiled-function-p (cdr arg))
 193                                      (and (eq (car-safe (cdr arg)) 'lambda)
 194                                           (assq 'byte-code (cdr arg))))))
 195                         (cond ((compiled-function-p arg)
 196                                (insert "<compiled-function>\n"))
 197                               ((eq (car-safe arg) 'lambda)
 198                                (insert "<compiled lambda>"))
 199                               (t (insert "<compiled macro>\n")))
 200                         (disassemble-internal
 201                          arg
 202                          (+ indent disassemble-recursive-indent 1)
 203                          nil))
 204                        ((eq (car-safe arg) 'byte-code)
 205                         (insert "<byte code>\n")
 206                         (disassemble-1  ;recurse on byte-code object
 207                          arg
 208                          (+ indent disassemble-recursive-indent)))
 209                        ((eq (car-safe (car-safe arg)) 'byte-code)
 210                         (insert "(<byte code>...)\n")
 211                         (mapcar ;recurse on list of byte-code objects
 212                          '(lambda (obj)
 213                             (disassemble-1
 214                              obj
 215                              (+ indent disassemble-recursive-indent)))
 216                          arg))
 217                        (t
 218                         ;; really just a constant
 219                         (let ((print-escape-newlines t))
 220                           (prin1 arg (current-buffer))))))
 221                 )
 222           (insert "\n"))
 223         (setq lap (cdr lap)))))
 224   nil)