summaryrefslogtreecommitdiff
path: root/etc/emacs-buffer.gdb
blob: 76586e2aff772ccbba384878d864ad13431d3caf (plain)
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
# emacs-buffer.gdb --- gdb macros for recovering buffers from emacs coredumps

# Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.

# Maintainer: Noah Friedman <friedman@splode.com>
# Status: Works with Emacs 22.0.51.1 (prerelease) as of 2006-01-12.
#         Older cvs snapshots, and released versions, will not work due to
#         changes in lisp data structures.  But there are older versions of
#         this gdb script which work with those versions.
# Created: 2005-04-28

# 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, 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; see the file COPYING.  If not, write to the
# Free Software Foundation, Inc.; 51 Franklin Street, Fifth Floor;
# Boston, MA 02110-1301, USA.

# 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.
#
# The Emacs executable must have debugging symbols for this to work.
# But you never strip Emacs, right?
#
# The main commands of interest are `ybuffer-list', `yfile-buffers',
# `ysave-buffer', and `ybuffer-contents'.  The `y' prefix avoids any
# namespace collisions with emacs/src/.gdbinit.

# 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:

# Force loading of symbols, enough to give us gdb_valbits etc.
set main

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

set $tagmask = (((long)1 << gdb_gctypebits) - 1)
set $valmask = gdb_use_lsb ? ~($tagmask) : ((long)1 << gdb_valbits) - 1

define ygetptr
  set $ptr = $arg0
  set $ptr = (gdb_use_union ? $ptr.u.val : $ptr & $valmask) | gdb_data_seg_bits
end

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
  while $alist != Qnil
    ygetptr $alist
    set $this  = ((struct Lisp_Cons *) $ptr)->car
    set $alist = ((struct Lisp_Cons *) $ptr)->u.cdr

    # Vbuffer_alist elts are pairs of the form (name . buffer)
    ygetptr $this
    set $buf  = ((struct Lisp_Cons *) $ptr)->u.cdr
    ygetptr $buf
    set $buf = (struct buffer *) $ptr

    if ! ($files_only && $buf->filename == Qnil)
      ygetptr $buf->name
      set $name = ((struct Lisp_String *) $ptr)->data
      set $modp = ($buf->text->modiff > $buf->text->save_modiff) ? '*' : ' '

      ygetptr $buf->mode_name
      set $mode = ((struct Lisp_String *) $ptr)->data

      if $buf->filename != Qnil
        ygetptr $buf->filename
        printf "%2d %c  %9d %-20s %-10s %s\n", \
               $i, $modp, ($buf->text->z_byte - 1), $name, $mode, \
               ((struct Lisp_String *) $ptr)->data
      else
        printf "%2d %c  %9d %-20s %-10s\n", \
               $i, $modp, ($buf->text->z_byte - 1), $name, $mode
      end
    end

    set $i++
  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
  to some other emacs-buffer recovery commands, e.g. `ysave-buffer'.
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.
  This is like `ybuffer-list', but only buffers that were visiting files
  are displayed.
end

define yset-buffer
  set $i = $arg0

  set $alist = Vbuffer_alist
  while ($alist != Qnil && $i > 0)
    ygetptr $alist
    set $alist = ((struct Lisp_Cons *) $ptr)->u.cdr
    set $i--
  end

  # Get car of alist; this is a pair (name . buffer)
  ygetptr $alist
  set $this = ((struct Lisp_Cons *) $ptr)->car

  # Get the buffer object
  ygetptr $this
  set $this = ((struct Lisp_Cons *) $ptr)->u.cdr

  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
  buffer as displayed by `ybuffer-list'.
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
  as displayed by `ybuffer-list'.

  This also sets the current buffer using `yset-buffer' (which see).
end

define yget-current-buffer-name
  set $this = $ycurrent_buffer->name
  ygetptr $this
  set $ycurrent_buffer_name = ((struct Lisp_String *) $ptr)->data
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
      dump   binary memory $arg1 $beg $gap-1
      append binary memory $arg1 $gap_end $end
      set $endptr = $end
    end
  end
end
document ydump-buffer
  Write contents of buffer N (as numbered according to `ybuffer-list') to
  file FILE.

  This is mainly used as an internal subroutine for `ysave-buffer' and
  `ybuffer-contents', which see.
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
  Save contents of buffer N (as numbered according to `ybuffer-list') to
  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
  Write contents of buffer N (numbered according to `ybuffer-list') to stdout.
end

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

# arch-tag: 02087f62-2663-4868-977a-1fbb2fc2e7ef