1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280
|
;;; disass.el --- disassembler for compiled Emacs Lisp code -*- lexical-binding:t -*-
;; Copyright (C) 1986, 1991, 2002-2020 Free Software Foundation, Inc.
;; Author: Doug Cutting <doug@csli.stanford.edu>
;; Jamie Zawinski <jwz@lucid.com>
;; Maintainer: emacs-devel@gnu.org
;; Keywords: internal
;; 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 3 of the License, 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. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; The single entry point, `disassemble', disassembles a code object generated
;; by the Emacs Lisp byte-compiler. This doesn't invert the compilation
;; operation, not by a long shot, but it's useful for debugging.
;;
;; Original version by Doug Cutting (doug@csli.stanford.edu)
;; Substantially modified by Jamie Zawinski <jwz@lucid.com> for
;; the new lapcode-based byte compiler.
;;; Code:
(require 'macroexp)
(require 'cl-lib)
;; The variable byte-code-vector is defined by the new bytecomp.el.
;; The function byte-decompile-lapcode is defined in byte-opt.el.
;; Since we don't use byte-decompile-lapcode, let's try not loading byte-opt.
(require 'byte-compile "bytecomp")
(defvar disassemble-column-1-indent 8 "*")
(defvar disassemble-column-2-indent 10 "*")
(defvar disassemble-recursive-indent 3 "*")
;;;###autoload
(defun disassemble (object &optional buffer indent interactive-p)
"Print disassembled code for OBJECT in (optional) BUFFER.
OBJECT can be a symbol defined as a function, or a function itself
\(a lambda expression or a compiled-function object).
If OBJECT is not already compiled, we compile it, but do not
redefine OBJECT if it is a symbol."
(interactive
(let* ((fn (function-called-at-point))
(prompt (if fn (format "Disassemble function (default %s): " fn)
"Disassemble function: "))
(def (and fn (symbol-name fn))))
(list (intern (completing-read prompt obarray 'fboundp t nil nil def))
nil 0 t)))
(if (and (consp object) (not (functionp object)))
(setq object `(lambda () ,object)))
(or indent (setq indent 0)) ;Default indent to zero
(save-excursion
(if (or interactive-p (null buffer))
(with-output-to-temp-buffer "*Disassemble*"
(set-buffer "*Disassemble*")
(disassemble-internal object indent (not interactive-p)))
(set-buffer buffer)
(disassemble-internal object indent nil)))
nil)
(defun disassemble-internal (obj indent interactive-p)
(let ((macro 'nil)
(name (when (symbolp obj)
(prog1 obj
(setq obj (indirect-function obj)))))
args)
(setq obj (autoload-do-load obj name))
(if (subrp obj)
(error "Can't disassemble #<subr %s>" name))
(if (eq (car-safe obj) 'macro) ;Handle macros.
(setq macro t
obj (cdr obj)))
(if (eq (car-safe obj) 'byte-code)
(setq obj `(lambda () ,obj)))
(when (consp obj)
(unless (functionp obj) (error "not a function"))
(if (assq 'byte-code obj)
nil
(if interactive-p (message (if name
"Compiling %s's definition..."
"Compiling definition...")
name))
(setq obj (byte-compile obj))
(if interactive-p (message "Done compiling. Disassembling..."))))
(cond ((consp obj)
(setq args (help-function-arglist obj)) ;save arg list
(setq obj (cdr obj)) ;throw lambda away
(setq obj (cdr obj)))
((byte-code-function-p obj)
(setq args (help-function-arglist obj)))
(t (error "Compilation failed")))
(if (zerop indent) ; not a nested function
(progn
(indent-to indent)
(insert (format "byte code%s%s%s:\n"
(if (or macro name) " for" "")
(if macro " macro" "")
(if name (format " %s" name) "")))))
(let ((doc (if (consp obj)
(and (stringp (car obj)) (car obj))
;; Use documentation to get lazy-loaded doc string
(documentation obj t))))
(if (and doc (stringp doc))
(progn (and (consp obj) (setq obj (cdr obj)))
(indent-to indent)
(princ " doc: " (current-buffer))
(if (string-match "\n" doc)
(setq doc (concat (substring doc 0 (match-beginning 0))
" ...")))
(insert doc "\n"))))
(indent-to indent)
(insert " args: ")
(prin1 args (current-buffer))
(insert "\n")
(let ((interactive (interactive-form obj)))
(if interactive
(progn
(setq interactive (nth 1 interactive))
(if (eq (car-safe (car-safe obj)) 'interactive)
(setq obj (cdr obj)))
(indent-to indent)
(insert " interactive: ")
(if (eq (car-safe interactive) 'byte-code)
(progn
(insert "\n")
(disassemble-1 interactive
(+ indent disassemble-recursive-indent)))
(let ((print-escape-newlines t))
(prin1 interactive (current-buffer))))
(insert "\n"))))
(cond ((and (consp obj) (assq 'byte-code obj))
(disassemble-1 (assq 'byte-code obj) indent))
((byte-code-function-p obj)
(disassemble-1 obj indent))
(t
(insert "Uncompiled body: ")
(let ((print-escape-newlines t))
(prin1 (macroexp-progn obj)
(current-buffer))))))
(if interactive-p
(message "")))
(defun disassemble-1 (obj indent)
"Prints the byte-code call OBJ in the current buffer.
OBJ should be a call to BYTE-CODE generated by the byte compiler."
(let (bytes constvec)
(if (consp obj)
(setq bytes (car (cdr obj)) ;the byte code
constvec (car (cdr (cdr obj)))) ;constant vector
;; If it is lazy-loaded, load it now
(fetch-bytecode obj)
(setq bytes (aref obj 1)
constvec (aref obj 2)))
(cl-assert (not (multibyte-string-p bytes)))
(let ((lap (byte-decompile-bytecode bytes constvec))
op arg opname pc-value)
(let ((tagno 0)
tmp
(lap lap))
(while (setq tmp (assq 'TAG lap))
(setcar (cdr tmp) (setq tagno (1+ tagno)))
(setq lap (cdr (memq tmp lap)))))
(while lap
;; Take off the pc value of the next thing
;; and put it in pc-value.
(setq pc-value nil)
(if (numberp (car lap))
(setq pc-value (car lap)
lap (cdr lap)))
;; Fetch the next op and its arg.
(setq op (car (car lap))
arg (cdr (car lap)))
(setq lap (cdr lap))
(indent-to indent)
(if (eq 'TAG op)
(progn
;; We have a label. Display it, but first its pc value.
(if pc-value
(insert (format "%d:" pc-value)))
(insert (int-to-string (car arg))))
;; We have an instruction. Display its pc value first.
(if pc-value
(insert (format "%d" pc-value)))
(indent-to (+ indent disassemble-column-1-indent))
(if (and op
(string-match "^byte-" (setq opname (symbol-name op))))
(setq opname (substring opname 5))
(setq opname "<not-an-opcode>"))
(if (eq op 'byte-constant2)
(insert " #### shouldn't have seen constant2 here!\n "))
(insert opname)
(indent-to (+ indent disassemble-column-1-indent
disassemble-column-2-indent
-1))
(insert " ")
(cond ((memq op byte-goto-ops)
(insert (int-to-string (nth 1 arg))))
((memq op '(byte-call byte-unbind
byte-listN byte-concatN byte-insertN
byte-stack-ref byte-stack-set byte-stack-set2
byte-discardN byte-discardN-preserve-tos))
(insert (int-to-string arg)))
((memq op '(byte-varref byte-varset byte-varbind))
(prin1 (car arg) (current-buffer)))
((memq op '(byte-constant byte-constant2))
;; it's a constant
(setq arg (car arg))
;; if the succeeding op is byte-switch, display the jump table
;; used
(cond ((eq (car-safe (car-safe (cdr lap))) 'byte-switch)
(insert (format "<jump-table-%s (" (hash-table-test arg)))
(let ((first-time t))
(maphash #'(lambda (value tag)
(if first-time
(setq first-time nil)
(insert " "))
(insert (format "%s %s" value (cadr tag))))
arg))
(insert ")>"))
;; if the value of the constant is compiled code, then
;; recursively disassemble it.
((or (byte-code-function-p arg)
(and (consp arg) (functionp arg)
(assq 'byte-code arg))
(and (eq (car-safe arg) 'macro)
(or (byte-code-function-p (cdr arg))
(and (consp (cdr arg))
(functionp (cdr arg))
(assq 'byte-code (cdr arg))))))
(cond ((byte-code-function-p arg)
(insert "<compiled-function>\n"))
((functionp arg)
(insert "<compiled lambda>"))
(t (insert "<compiled macro>\n")))
(disassemble-internal
arg
(+ indent disassemble-recursive-indent 1)
nil))
((eq (car-safe arg) 'byte-code)
(insert "<byte code>\n")
(disassemble-1 ;recurse on byte-code object
arg
(+ indent disassemble-recursive-indent)))
((eq (car-safe (car-safe arg)) 'byte-code)
(insert "(<byte code>...)\n")
(mapc ;recurse on list of byte-code objects
(lambda (obj)
(disassemble-1
obj
(+ indent disassemble-recursive-indent)))
arg))
(t
;; really just a constant
(let ((print-escape-newlines t))
(prin1 arg (current-buffer))))))
)
(insert "\n")))))
nil)
(provide 'disass)
;;; disass.el ends here
|