emacs-buffer.gdb 8.56 KB
Newer Older
Noah Friedman's avatar
Noah Friedman committed
1 2
# emacs-buffer.gdb --- gdb macros for recovering buffers from emacs coredumps

3
# Copyright (C) 2005-2019 Free Software Foundation, Inc.
Noah Friedman's avatar
Noah Friedman committed
4

Noah Friedman's avatar
Noah Friedman committed
5
# Author: Noah Friedman <friedman@splode.com>
Noah Friedman's avatar
Noah Friedman committed
6 7 8
# Created: 2005-04-28

# This file is part of GNU Emacs.
9 10

# GNU Emacs is free software: you can redistribute it and/or modify
Noah Friedman's avatar
Noah Friedman committed
11
# it under the terms of the GNU General Public License as published by
12 13 14
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

Noah Friedman's avatar
Noah Friedman committed
15 16 17 18
# 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.
19

Noah Friedman's avatar
Noah Friedman committed
20
# You should have received a copy of the GNU General Public License
21
# along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
Noah Friedman's avatar
Noah Friedman committed
22 23 24 25 26 27 28

# Commentary:

# This is a set of gdb macros for recovering the contents of buffers from
# an Emacs coredump; they may not always be file-backed or have a recent
# autosave.
#
29 30
# The Emacs executable must have debugging symbols for this to work.
# But you never strip Emacs, right?
Noah Friedman's avatar
Noah Friedman committed
31
#
32 33
# The main commands of interest are 'ybuffer-list', 'yfile-buffers',
# 'ysave-buffer', and 'ybuffer-contents'.  The 'y' prefix avoids any
Noah Friedman's avatar
Noah Friedman committed
34 35
# namespace collisions with emacs/src/.gdbinit.

36
# Since the internal data structures in Emacs change from time to
37 38 39
# time, you should use the version of this file that came with your
# particular Emacs version; older versions might not work anymore.

Noah Friedman's avatar
Noah Friedman committed
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
# Example usage:
#
#     $ gdb /export/src/emacs/2005-05-02--03-17/src/emacs core.emacs.6.9845
#     Current directory is /u/noah/
#     GNU gdb (6.1post-1.20040607.43rh)
#     ...
#     #0  0x400007a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
#     (gdb) source emacs-buffer.gdb
#     (gdb) ybuffer-list
#     B# M       Size Name                 Mode       File
#     -- -       ---- ----                 ----       ----
#      0 *        556 mail to emacs-devel@gnu.org Mail
#      1 *          0  *Minibuf-1*         Fundamental
#      2       145769 ChangeLog            Change Log /u/noah/lib/elisp/noahf/ChangeLog
#      3         6619 ascii-table.el       Elisp      /u/noah/lib/elisp/noahf/ascii-table.el
#      4 *      48396 *Messages*           Fundamental
#      5         3191 *Apropos*            Apropos
#      6        17642 init-21.el           Elisp      /u/noah/etc/init/emacs/init-21.el
#      7          333 cpuid.c              C          /u/noah/cpuid.c
#      8          230 src                  Dired
#      9          218 noah                 Dired
#     10 *         21  *Echo Area 0*       Fundamental
#     11 *          0  *Echo Area 1*       Fundamental
#     12       319952  *bbdb data*         Text       /u/noah/.bbdb
#     (gdb) ysave-buffer 0 mail.save
#     [Wrote buffer "mail to emacs-devel@gnu.org" to file mail.save]
#     (gdb) quit
#     $ ls -l mail.save
#     -rw-rw-rw-  1 noah user 556 May  2 04:05 mail.save
#     $

# Code:

73 74 75 76
# Force loading of symbols, enough to give us VALBITS etc.
set $dummy = main + 8
# With some compilers, we need this to give us struct Lisp_Symbol etc.:
set $dummy = Fmake_symbol + 8
Noah Friedman's avatar
Noah Friedman committed
77 78 79 80 81 82 83

# When nonzero, display some extra diagnostics in various commands
set $yverbose = 1
set $yfile_buffers_only = 0

define ygetptr
  set $ptr = $arg0
84
  set $ptr = (EMACS_INT) (CHECK_LISP_OBJECT_TYPE ? $ptr.i : $ptr) & VALMASK
Noah Friedman's avatar
Noah Friedman committed
85 86
end

87 88 89 90 91
# Get the value of Qnil for comparison.  Needed when
# CHECK_LISP_OBJECT_TYPE is non-zero.
ygetptr Qnil
set $qnil = $ptr

Noah Friedman's avatar
Noah Friedman committed
92 93 94 95 96 97 98 99 100 101 102
define ybuffer-list
  set $files_only         = $yfile_buffers_only
  set $yfile_buffers_only = 0

  if $yverbose
    printf "B# M       Size Name                 Mode       File\n"
    printf "-- -       ---- ----                 ----       ----\n"
  end

  set $i = 0
  set $alist = Vbuffer_alist
103 104 105
  ygetptr $alist
  set $alist = $ptr
  while $alist != $qnil
106 107
    set $this  = ((struct Lisp_Cons *) $ptr)->u.s.car
    set $alist = ((struct Lisp_Cons *) $ptr)->u.s.u.cdr
Noah Friedman's avatar
Noah Friedman committed
108 109 110

    # Vbuffer_alist elts are pairs of the form (name . buffer)
    ygetptr $this
111
    set $buf  = ((struct Lisp_Cons *) $ptr)->u.s.u.cdr
Noah Friedman's avatar
Noah Friedman committed
112 113 114
    ygetptr $buf
    set $buf = (struct buffer *) $ptr

115 116 117
    ygetptr $buf->filename_
    set $fname = $ptr
    if ! ($files_only && $fname == $qnil)
118
      ygetptr $buf->name_
119
      set $name = ((struct Lisp_String *) $ptr)->u.s.data
Noah Friedman's avatar
Noah Friedman committed
120 121
      set $modp = ($buf->text->modiff > $buf->text->save_modiff) ? '*' : ' '

122
      ygetptr $buf->mode_name_
123
      set $mode = ((struct Lisp_String *) $ptr)->u.s.data
Noah Friedman's avatar
Noah Friedman committed
124

125
      if $fname != $qnil
126
        ygetptr $buf->filename_
127 128
        printf "%2d %c  %9d %-20s %-10s %s\n", \
               $i, $modp, ($buf->text->z_byte - 1), $name, $mode, \
129
               ((struct Lisp_String *) $fname)->u.s.data
Noah Friedman's avatar
Noah Friedman committed
130
      else
131 132
        printf "%2d %c  %9d %-20s %-10s\n", \
               $i, $modp, ($buf->text->z_byte - 1), $name, $mode
Noah Friedman's avatar
Noah Friedman committed
133 134 135 136
      end
    end

    set $i++
137 138
    ygetptr $alist
    set $alist = $ptr
Noah Friedman's avatar
Noah Friedman committed
139 140 141 142 143
  end
end
document ybuffer-list
  Display a list of buffer names, sizes, and other attributes.
  The buffer number in the first column is used as an argument
144
  to some other emacs-buffer recovery commands, e.g. 'ysave-buffer'.
Noah Friedman's avatar
Noah Friedman committed
145 146 147 148 149 150 151 152
end

define yfile-buffers
  set $yfile_buffers_only = 1
  ybuffer-list
end
document yfile-buffers
  Display a list of buffers which are associated with files.
153
  This is like 'ybuffer-list', but only buffers that were visiting files
Noah Friedman's avatar
Noah Friedman committed
154 155 156 157 158 159 160
  are displayed.
end

define yset-buffer
  set $i = $arg0

  set $alist = Vbuffer_alist
161 162 163
  ygetptr $alist
  set $alist = $ptr
  while ($alist != $qnil && $i > 0)
164
    set $alist = ((struct Lisp_Cons *) $ptr)->u.s.u.cdr
165 166
    ygetptr $alist
    set $alist = $ptr
Noah Friedman's avatar
Noah Friedman committed
167 168 169 170
    set $i--
  end

  # Get car of alist; this is a pair (name . buffer)
171
  set $this = ((struct Lisp_Cons *) $alist)->u.s.car
Noah Friedman's avatar
Noah Friedman committed
172 173 174

  # Get the buffer object
  ygetptr $this
175
  set $this = ((struct Lisp_Cons *) $ptr)->u.s.u.cdr
Noah Friedman's avatar
Noah Friedman committed
176 177 178 179 180 181

  ygetptr $this
  set $ycurrent_buffer = (struct buffer *) $ptr
end
document yset-buffer
  Set current buffer (for other emacs-buffer recovery commands) to the ARG'th
182
  buffer as displayed by 'ybuffer-list'.
Noah Friedman's avatar
Noah Friedman committed
183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200
end

define yget-buffer-pointers
  yset-buffer $arg0
  set $buf = $ycurrent_buffer->text

  set $beg     = $buf->beg
  set $gap     = $beg + $buf->gpt_byte
  set $gap_end = $gap + $buf->gap_size - 1
  set $end     = $gap_end + ($buf->z_byte - $buf->gpt_byte)

  set $modp    = $buf->modiff > $buf->save_modiff

  #print *$beg@($gap - $beg)
  #print *$gap_end@($end - $gap_end)
end
document yget-buffer-pointers
  Update convenience variables with address pointers for the ARG'th buffer
201
  as displayed by 'ybuffer-list'.
Noah Friedman's avatar
Noah Friedman committed
202

203
  This also sets the current buffer using 'yset-buffer' (which see).
Noah Friedman's avatar
Noah Friedman committed
204 205 206
end

define yget-current-buffer-name
207
  set $this = $ycurrent_buffer->name_
Noah Friedman's avatar
Noah Friedman committed
208
  ygetptr $this
209
  set $ycurrent_buffer_name = ((struct Lisp_String *) $ptr)->u.s.data
Noah Friedman's avatar
Noah Friedman committed
210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229
end
document yget-current-buffer-name
  Set $ycurrent_buffer_name to the name of the currently selected buffer.
end

define ycurrent-buffer
  yget-current-buffer-name
  printf "%s\n", $ycurrent_buffer_name
end
document ycurrent-buffer
  Display the currently selected buffer.
end

define ydump-buffer
  yget-buffer-pointers $arg0
  if $buf->z_byte > 1
    if $buf->z_byte <= $buf->gpt_byte
      set $endptr = $beg + $buf->gpt_byte - 1
      dump binary memory $arg1 $beg $endptr
    else
230 231 232 233 234 235
      if $gap - $beg > 1
        dump   binary memory $arg1 $beg $gap-1
        append binary memory $arg1 $gap_end $end
      else
        dump   binary memory $arg1 $gap_end $end
      end
Noah Friedman's avatar
Noah Friedman committed
236 237 238 239 240
      set $endptr = $end
    end
  end
end
document ydump-buffer
241
  Write contents of buffer N (as numbered according to 'ybuffer-list') to
Noah Friedman's avatar
Noah Friedman committed
242 243
  file FILE.

244 245
  This is mainly used as an internal subroutine for 'ysave-buffer' and
  'ybuffer-contents', which see.
Noah Friedman's avatar
Noah Friedman committed
246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262
end

define ysave-buffer
  ydump-buffer $arg0 $arg1
  if $yverbose
    yget-current-buffer-name
    if $buf->z_byte <= 1
      printf "[Buffer \"%s\" is empty.]\n", $ycurrent_buffer_name
    else
      # Output string broken into separate calls as necessary to avoid
      # requiring a running process for evaluation.
      printf "[Wrote buffer \"%s\" to file ", $ycurrent_buffer_name
      echo $arg1]\n
    end
  end
end
document ysave-buffer
263
  Save contents of buffer N (as numbered according to 'ybuffer-list') to
Noah Friedman's avatar
Noah Friedman committed
264 265 266 267 268 269 270 271 272 273 274 275 276 277 278
  file FILE.
end

define ybuffer-contents
  ydump-buffer $arg0 /dev/stdout
  if $yverbose && $buf->z_byte <= 1
    yget-current-buffer-name
    printf "[Buffer \"%s\" is empty.]\n", $ycurrent_buffer_name
  else
    if *($endptr-1) != '\n'
      echo \n
    end
  end
end
document ybuffer-contents
279
  Write contents of buffer N (numbered according to 'ybuffer-list') to stdout.
Noah Friedman's avatar
Noah Friedman committed
280 281 282 283 284
end

# local variables:
# mode: gdb-script
# end: