Commit | Line | Data |
---|---|---|
c6953be1 | 1 | /* undo handling for GNU Emacs. |
73b0cd50 | 2 | Copyright (C) 1990, 1993-1994, 2000-2011 Free Software Foundation, Inc. |
c6953be1 JB |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
3b7ad313 | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
3b7ad313 | 10 | |
c6953be1 | 11 | GNU Emacs is distributed in the hope that it will be useful, |
3b7ad313 EN |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
c6953be1 JB |
18 | |
19 | ||
18160b98 | 20 | #include <config.h> |
d7306fe6 | 21 | #include <setjmp.h> |
c6953be1 JB |
22 | #include "lisp.h" |
23 | #include "buffer.h" | |
4e665715 | 24 | #include "commands.h" |
91e25f5e | 25 | #include "window.h" |
c6953be1 JB |
26 | |
27 | /* Last buffer for which undo information was recorded. */ | |
4591d6cb | 28 | /* BEWARE: This is not traced by the GC, so never dereference it! */ |
2b96acb7 | 29 | static struct buffer *last_undo_buffer; |
4591d6cb SM |
30 | |
31 | /* Position of point last time we inserted a boundary. */ | |
2b96acb7 PE |
32 | static struct buffer *last_boundary_buffer; |
33 | static EMACS_INT last_boundary_position; | |
c6953be1 | 34 | |
f87a68b3 RS |
35 | Lisp_Object Qinhibit_read_only; |
36 | ||
49be18c9 KS |
37 | /* Marker for function call undo list elements. */ |
38 | ||
39 | Lisp_Object Qapply; | |
40 | ||
c58632fc RS |
41 | /* The first time a command records something for undo. |
42 | it also allocates the undo-boundary object | |
43 | which will be added to the list at the end of the command. | |
44 | This ensures we can't run out of space while trying to make | |
45 | an undo-boundary. */ | |
2b96acb7 | 46 | static Lisp_Object pending_boundary; |
c58632fc | 47 | |
6396140a | 48 | /* Record point as it was at beginning of this command (if necessary) |
8abe0f97 | 49 | and prepare the undo info for recording a change. |
6396140a SM |
50 | PT is the position of point that will naturally occur as a result of the |
51 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 52 | |
6396140a | 53 | static void |
c8a66ab8 | 54 | record_point (EMACS_INT pt) |
c6953be1 | 55 | { |
6396140a | 56 | int at_boundary; |
bdbe6f28 | 57 | |
4591d6cb | 58 | /* Don't record position of pt when undo_inhibit_record_point holds. */ |
8abe0f97 MR |
59 | if (undo_inhibit_record_point) |
60 | return; | |
61 | ||
c58632fc RS |
62 | /* Allocate a cons cell to be the undo boundary after this command. */ |
63 | if (NILP (pending_boundary)) | |
64 | pending_boundary = Fcons (Qnil, Qnil); | |
65 | ||
3ecc1163 MR |
66 | if ((current_buffer != last_undo_buffer) |
67 | /* Don't call Fundo_boundary for the first change. Otherwise we | |
68 | risk overwriting last_boundary_position in Fundo_boundary with | |
69 | PT of the current buffer and as a consequence not insert an | |
70 | undo boundary because last_boundary_position will equal pt in | |
71 | the test at the end of the present function (Bug#731). */ | |
72 | && (MODIFF > SAVE_MODIFF)) | |
c6953be1 | 73 | Fundo_boundary (); |
4591d6cb | 74 | last_undo_buffer = current_buffer; |
c6953be1 | 75 | |
4b4deea2 | 76 | if (CONSP (BVAR (current_buffer, undo_list))) |
6396140a SM |
77 | { |
78 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
79 | marker adjustment before undo boundary. */ | |
80 | ||
4b4deea2 | 81 | Lisp_Object tail = BVAR (current_buffer, undo_list), elt; |
6396140a SM |
82 | |
83 | while (1) | |
84 | { | |
85 | if (NILP (tail)) | |
86 | elt = Qnil; | |
87 | else | |
88 | elt = XCAR (tail); | |
89 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
90 | break; | |
91 | tail = XCDR (tail); | |
92 | } | |
93 | at_boundary = NILP (elt); | |
94 | } | |
95 | else | |
96 | at_boundary = 1; | |
97 | ||
ad9cdce4 | 98 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
99 | record_first_change (); |
100 | ||
177c0ea7 | 101 | /* If we are just after an undo boundary, and |
6396140a SM |
102 | point wasn't at start of deleted range, record where it was. */ |
103 | if (at_boundary | |
4591d6cb SM |
104 | && current_buffer == last_boundary_buffer |
105 | && last_boundary_position != pt) | |
4b4deea2 TT |
106 | BVAR (current_buffer, undo_list) |
107 | = Fcons (make_number (last_boundary_position), BVAR (current_buffer, undo_list)); | |
6396140a SM |
108 | } |
109 | ||
110 | /* Record an insertion that just happened or is about to happen, | |
111 | for LENGTH characters at position BEG. | |
112 | (It is possible to record an insertion before or after the fact | |
113 | because we don't need to record the contents.) */ | |
114 | ||
115 | void | |
c8a66ab8 | 116 | record_insert (EMACS_INT beg, EMACS_INT length) |
6396140a SM |
117 | { |
118 | Lisp_Object lbeg, lend; | |
119 | ||
4b4deea2 | 120 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
6396140a SM |
121 | return; |
122 | ||
123 | record_point (beg); | |
124 | ||
c6953be1 JB |
125 | /* If this is following another insertion and consecutive with it |
126 | in the buffer, combine the two. */ | |
4b4deea2 | 127 | if (CONSP (BVAR (current_buffer, undo_list))) |
c6953be1 JB |
128 | { |
129 | Lisp_Object elt; | |
4b4deea2 | 130 | elt = XCAR (BVAR (current_buffer, undo_list)); |
38c0d37c | 131 | if (CONSP (elt) |
c1d497be KR |
132 | && INTEGERP (XCAR (elt)) |
133 | && INTEGERP (XCDR (elt)) | |
134 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 135 | { |
f3fbd155 | 136 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
137 | return; |
138 | } | |
139 | } | |
140 | ||
53480e99 KH |
141 | XSETFASTINT (lbeg, beg); |
142 | XSETINT (lend, beg + length); | |
4b4deea2 TT |
143 | BVAR (current_buffer, undo_list) = Fcons (Fcons (lbeg, lend), |
144 | BVAR (current_buffer, undo_list)); | |
c6953be1 JB |
145 | } |
146 | ||
147 | /* Record that a deletion is about to take place, | |
e928d437 | 148 | of the characters in STRING, at location BEG. */ |
c6953be1 | 149 | |
ff1aa840 | 150 | void |
c8a66ab8 | 151 | record_delete (EMACS_INT beg, Lisp_Object string) |
c6953be1 | 152 | { |
e928d437 | 153 | Lisp_Object sbeg; |
c6953be1 | 154 | |
4b4deea2 | 155 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
bdbe6f28 RS |
156 | return; |
157 | ||
d5db4077 | 158 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 159 | { |
6396140a SM |
160 | XSETINT (sbeg, -beg); |
161 | record_point (PT); | |
cbc1b668 KH |
162 | } |
163 | else | |
6396140a SM |
164 | { |
165 | XSETFASTINT (sbeg, beg); | |
166 | record_point (beg); | |
167 | } | |
350bce56 | 168 | |
4b4deea2 TT |
169 | BVAR (current_buffer, undo_list) |
170 | = Fcons (Fcons (string, sbeg), BVAR (current_buffer, undo_list)); | |
c6953be1 JB |
171 | } |
172 | ||
714bced9 RS |
173 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
174 | This is done only when a marker points within text being deleted, | |
175 | because that's the only case where an automatic marker adjustment | |
176 | won't be inverted automatically by undoing the buffer modification. */ | |
177 | ||
ff1aa840 | 178 | void |
c8a66ab8 | 179 | record_marker_adjustment (Lisp_Object marker, EMACS_INT adjustment) |
714bced9 | 180 | { |
4b4deea2 | 181 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
714bced9 RS |
182 | return; |
183 | ||
184 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
185 | if (NILP (pending_boundary)) | |
186 | pending_boundary = Fcons (Qnil, Qnil); | |
187 | ||
4591d6cb | 188 | if (current_buffer != last_undo_buffer) |
714bced9 | 189 | Fundo_boundary (); |
4591d6cb | 190 | last_undo_buffer = current_buffer; |
714bced9 | 191 | |
4b4deea2 | 192 | BVAR (current_buffer, undo_list) |
714bced9 | 193 | = Fcons (Fcons (marker, make_number (adjustment)), |
4b4deea2 | 194 | BVAR (current_buffer, undo_list)); |
714bced9 RS |
195 | } |
196 | ||
c6953be1 JB |
197 | /* Record that a replacement is about to take place, |
198 | for LENGTH characters at location BEG. | |
e928d437 | 199 | The replacement must not change the number of characters. */ |
c6953be1 | 200 | |
ff1aa840 | 201 | void |
c8a66ab8 | 202 | record_change (EMACS_INT beg, EMACS_INT length) |
c6953be1 | 203 | { |
e928d437 | 204 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
205 | record_insert (beg, length); |
206 | } | |
207 | \f | |
208 | /* Record that an unmodified buffer is about to be changed. | |
209 | Record the file modification date so that when undoing this entry | |
210 | we can tell whether it is obsolete because the file was saved again. */ | |
211 | ||
90dd3e4f | 212 | void |
971de7fb | 213 | record_first_change (void) |
c6953be1 | 214 | { |
ad9cdce4 | 215 | struct buffer *base_buffer = current_buffer; |
0736cafe | 216 | |
4b4deea2 | 217 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
0736cafe RS |
218 | return; |
219 | ||
4591d6cb | 220 | if (current_buffer != last_undo_buffer) |
0736cafe | 221 | Fundo_boundary (); |
4591d6cb | 222 | last_undo_buffer = current_buffer; |
0736cafe | 223 | |
ad9cdce4 RS |
224 | if (base_buffer->base_buffer) |
225 | base_buffer = base_buffer->base_buffer; | |
226 | ||
be44ca6c PE |
227 | BVAR (current_buffer, undo_list) = |
228 | Fcons (Fcons (Qt, INTEGER_TO_CONS (base_buffer->modtime)), | |
229 | BVAR (current_buffer, undo_list)); | |
c6953be1 JB |
230 | } |
231 | ||
da9319d5 RS |
232 | /* Record a change in property PROP (whose old value was VAL) |
233 | for LENGTH characters starting at position BEG in BUFFER. */ | |
234 | ||
90dd3e4f | 235 | void |
c8a66ab8 EZ |
236 | record_property_change (EMACS_INT beg, EMACS_INT length, |
237 | Lisp_Object prop, Lisp_Object value, | |
238 | Lisp_Object buffer) | |
da9319d5 RS |
239 | { |
240 | Lisp_Object lbeg, lend, entry; | |
4591d6cb | 241 | struct buffer *obuf = current_buffer, *buf = XBUFFER (buffer); |
da9319d5 RS |
242 | int boundary = 0; |
243 | ||
4b4deea2 | 244 | if (EQ (BVAR (buf, undo_list), Qt)) |
bdbe6f28 RS |
245 | return; |
246 | ||
c58632fc RS |
247 | /* Allocate a cons cell to be the undo boundary after this command. */ |
248 | if (NILP (pending_boundary)) | |
249 | pending_boundary = Fcons (Qnil, Qnil); | |
250 | ||
4591d6cb | 251 | if (buf != last_undo_buffer) |
da9319d5 | 252 | boundary = 1; |
4591d6cb | 253 | last_undo_buffer = buf; |
da9319d5 | 254 | |
da9319d5 | 255 | /* Switch temporarily to the buffer that was changed. */ |
4591d6cb | 256 | current_buffer = buf; |
da9319d5 RS |
257 | |
258 | if (boundary) | |
259 | Fundo_boundary (); | |
260 | ||
ad9cdce4 | 261 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
262 | record_first_change (); |
263 | ||
552bdbcf KH |
264 | XSETINT (lbeg, beg); |
265 | XSETINT (lend, beg + length); | |
da9319d5 | 266 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
4b4deea2 | 267 | BVAR (current_buffer, undo_list) = Fcons (entry, BVAR (current_buffer, undo_list)); |
da9319d5 RS |
268 | |
269 | current_buffer = obuf; | |
270 | } | |
271 | ||
a7ca3326 | 272 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
273 | doc: /* Mark a boundary between units of undo. |
274 | An undo command will stop at this point, | |
275 | but another undo command will undo to the previous boundary. */) | |
5842a27b | 276 | (void) |
c6953be1 JB |
277 | { |
278 | Lisp_Object tem; | |
4b4deea2 | 279 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
c6953be1 | 280 | return Qnil; |
4b4deea2 | 281 | tem = Fcar (BVAR (current_buffer, undo_list)); |
265a9e55 | 282 | if (!NILP (tem)) |
c58632fc RS |
283 | { |
284 | /* One way or another, cons nil onto the front of the undo list. */ | |
285 | if (!NILP (pending_boundary)) | |
286 | { | |
287 | /* If we have preallocated the cons cell to use here, | |
288 | use that one. */ | |
4b4deea2 TT |
289 | XSETCDR (pending_boundary, BVAR (current_buffer, undo_list)); |
290 | BVAR (current_buffer, undo_list) = pending_boundary; | |
c58632fc RS |
291 | pending_boundary = Qnil; |
292 | } | |
293 | else | |
4b4deea2 | 294 | BVAR (current_buffer, undo_list) = Fcons (Qnil, BVAR (current_buffer, undo_list)); |
c58632fc | 295 | } |
4591d6cb SM |
296 | last_boundary_position = PT; |
297 | last_boundary_buffer = current_buffer; | |
c6953be1 JB |
298 | return Qnil; |
299 | } | |
300 | ||
301 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
302 | returning the truncated list. How this is done depends on the |
303 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
304 | In some cases this works by calling undo-outer-limit-function. */ | |
305 | ||
306 | void | |
971de7fb | 307 | truncate_undo_list (struct buffer *b) |
c6953be1 | 308 | { |
137e23ea | 309 | Lisp_Object list; |
c6953be1 JB |
310 | Lisp_Object prev, next, last_boundary; |
311 | int size_so_far = 0; | |
312 | ||
137e23ea RS |
313 | /* Make sure that calling undo-outer-limit-function |
314 | won't cause another GC. */ | |
315 | int count = inhibit_garbage_collection (); | |
316 | ||
317 | /* Make the buffer current to get its local values of variables such | |
318 | as undo_limit. Also so that Vundo_outer_limit_function can | |
319 | tell which buffer to operate on. */ | |
320 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
321 | set_buffer_internal (b); | |
322 | ||
4b4deea2 | 323 | list = BVAR (b, undo_list); |
137e23ea | 324 | |
c6953be1 JB |
325 | prev = Qnil; |
326 | next = list; | |
327 | last_boundary = Qnil; | |
328 | ||
137e23ea | 329 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 330 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
331 | { |
332 | /* Add in the space occupied by this element and its chain link. */ | |
333 | size_so_far += sizeof (struct Lisp_Cons); | |
334 | ||
335 | /* Advance to next element. */ | |
336 | prev = next; | |
c1d497be | 337 | next = XCDR (next); |
c6953be1 | 338 | } |
e3d5ca1e | 339 | |
137e23ea RS |
340 | /* Always preserve at least the most recent undo record |
341 | unless it is really horribly big. | |
342 | ||
343 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
344 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
345 | ||
c1d497be | 346 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
347 | { |
348 | Lisp_Object elt; | |
c1d497be | 349 | elt = XCAR (next); |
c6953be1 JB |
350 | |
351 | /* Add in the space occupied by this element and its chain link. */ | |
352 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 353 | if (CONSP (elt)) |
c6953be1 JB |
354 | { |
355 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 356 | if (STRINGP (XCAR (elt))) |
c6953be1 | 357 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 358 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
359 | } |
360 | ||
361 | /* Advance to next element. */ | |
362 | prev = next; | |
c1d497be | 363 | next = XCDR (next); |
c6953be1 | 364 | } |
e3d5ca1e | 365 | |
137e23ea RS |
366 | /* If by the first boundary we have already passed undo_outer_limit, |
367 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
368 | if (INTEGERP (Vundo_outer_limit) |
369 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
370 | && !NILP (Vundo_outer_limit_function)) |
371 | { | |
4591d6cb SM |
372 | Lisp_Object tem; |
373 | struct buffer *temp = last_undo_buffer; | |
137e23ea RS |
374 | |
375 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
376 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
377 | if (! NILP (tem)) | |
137e23ea RS |
378 | { |
379 | /* The function is responsible for making | |
380 | any desired changes in buffer-undo-list. */ | |
381 | unbind_to (count, Qnil); | |
382 | return; | |
383 | } | |
384 | /* That function probably used the minibuffer, and if so, that | |
385 | changed last_undo_buffer. Change it back so that we don't | |
386 | force next change to make an undo boundary here. */ | |
387 | last_undo_buffer = temp; | |
388 | } | |
389 | ||
38c0d37c | 390 | if (CONSP (next)) |
c6953be1 JB |
391 | last_boundary = prev; |
392 | ||
137e23ea | 393 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 394 | while (CONSP (next)) |
c6953be1 JB |
395 | { |
396 | Lisp_Object elt; | |
c1d497be | 397 | elt = XCAR (next); |
c6953be1 JB |
398 | |
399 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 400 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 401 | tells us to truncate after it. If its size pushes past |
137e23ea | 402 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 403 | if (NILP (elt)) |
c6953be1 | 404 | { |
137e23ea | 405 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
406 | break; |
407 | last_boundary = prev; | |
137e23ea | 408 | if (size_so_far > undo_limit) |
c6953be1 JB |
409 | break; |
410 | } | |
411 | ||
412 | /* Add in the space occupied by this element and its chain link. */ | |
413 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 414 | if (CONSP (elt)) |
c6953be1 JB |
415 | { |
416 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 417 | if (STRINGP (XCAR (elt))) |
c6953be1 | 418 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 419 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
420 | } |
421 | ||
422 | /* Advance to next element. */ | |
423 | prev = next; | |
c1d497be | 424 | next = XCDR (next); |
c6953be1 JB |
425 | } |
426 | ||
427 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 428 | if (NILP (next)) |
137e23ea | 429 | ; |
c6953be1 | 430 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
431 | else if (!NILP (last_boundary)) |
432 | XSETCDR (last_boundary, Qnil); | |
433 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 434 | else |
4b4deea2 | 435 | BVAR (b, undo_list) = Qnil; |
137e23ea RS |
436 | |
437 | unbind_to (count, Qnil); | |
c6953be1 JB |
438 | } |
439 | \f | |
440 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
441 | doc: /* Undo N records from the front of the list LIST. |
442 | Return what remains of the list. */) | |
5842a27b | 443 | (Lisp_Object n, Lisp_Object list) |
c6953be1 | 444 | { |
de65837b KH |
445 | struct gcpro gcpro1, gcpro2; |
446 | Lisp_Object next; | |
331379bf | 447 | int count = SPECPDL_INDEX (); |
de65837b | 448 | register int arg; |
4ac03187 KS |
449 | Lisp_Object oldlist; |
450 | int did_apply = 0; | |
177c0ea7 | 451 | |
c6953be1 JB |
452 | #if 0 /* This is a good feature, but would make undo-start |
453 | unable to do what is expected. */ | |
454 | Lisp_Object tem; | |
455 | ||
456 | /* If the head of the list is a boundary, it is the boundary | |
457 | preceding this command. Get rid of it and don't count it. */ | |
458 | tem = Fcar (list); | |
265a9e55 | 459 | if (NILP (tem)) |
c6953be1 JB |
460 | list = Fcdr (list); |
461 | #endif | |
462 | ||
b7826503 | 463 | CHECK_NUMBER (n); |
de65837b KH |
464 | arg = XINT (n); |
465 | next = Qnil; | |
466 | GCPRO2 (next, list); | |
4ac03187 KS |
467 | /* I don't think we need to gcpro oldlist, as we use it only |
468 | to check for EQ. ++kfs */ | |
de65837b | 469 | |
38d56be3 GM |
470 | /* In a writable buffer, enable undoing read-only text that is so |
471 | because of text properties. */ | |
4b4deea2 | 472 | if (NILP (BVAR (current_buffer, read_only))) |
f87a68b3 RS |
473 | specbind (Qinhibit_read_only, Qt); |
474 | ||
8c757fd7 GM |
475 | /* Don't let `intangible' properties interfere with undo. */ |
476 | specbind (Qinhibit_point_motion_hooks, Qt); | |
477 | ||
4b4deea2 | 478 | oldlist = BVAR (current_buffer, undo_list); |
4ac03187 | 479 | |
c6953be1 JB |
480 | while (arg > 0) |
481 | { | |
c3b09bbf | 482 | while (CONSP (list)) |
c6953be1 | 483 | { |
c3b09bbf SM |
484 | next = XCAR (list); |
485 | list = XCDR (list); | |
350bce56 | 486 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 487 | if (NILP (next)) |
c6953be1 | 488 | break; |
350bce56 | 489 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 490 | if (INTEGERP (next)) |
350bce56 | 491 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 492 | else if (CONSP (next)) |
c6953be1 | 493 | { |
350bce56 RS |
494 | Lisp_Object car, cdr; |
495 | ||
c3b09bbf SM |
496 | car = XCAR (next); |
497 | cdr = XCDR (next); | |
350bce56 | 498 | if (EQ (car, Qt)) |
c6953be1 | 499 | { |
350bce56 | 500 | /* Element (t high . low) records previous modtime. */ |
ad9cdce4 | 501 | struct buffer *base_buffer = current_buffer; |
be44ca6c PE |
502 | time_t mod_time; |
503 | CONS_TO_INTEGER (cdr, time_t, mod_time); | |
ad9cdce4 RS |
504 | |
505 | if (current_buffer->base_buffer) | |
506 | base_buffer = current_buffer->base_buffer; | |
507 | ||
350bce56 RS |
508 | /* If this records an obsolete save |
509 | (not matching the actual disk file) | |
510 | then don't mark unmodified. */ | |
ad9cdce4 | 511 | if (mod_time != base_buffer->modtime) |
103dcb38 | 512 | continue; |
e6dd6080 | 513 | #ifdef CLASH_DETECTION |
350bce56 | 514 | Funlock_buffer (); |
e6dd6080 | 515 | #endif /* CLASH_DETECTION */ |
350bce56 | 516 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 517 | } |
d8552b2f | 518 | else if (EQ (car, Qnil)) |
da9319d5 | 519 | { |
6887bce5 | 520 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
521 | Lisp_Object beg, end, prop, val; |
522 | ||
523 | prop = Fcar (cdr); | |
524 | cdr = Fcdr (cdr); | |
525 | val = Fcar (cdr); | |
526 | cdr = Fcdr (cdr); | |
527 | beg = Fcar (cdr); | |
528 | end = Fcdr (cdr); | |
529 | ||
9e568684 CY |
530 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
531 | error ("Changes to be undone are outside visible portion of buffer"); | |
da9319d5 RS |
532 | Fput_text_property (beg, end, prop, val, Qnil); |
533 | } | |
38c0d37c | 534 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 535 | { |
350bce56 | 536 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
537 | |
538 | if (XINT (car) < BEGV | |
539 | || XINT (cdr) > ZV) | |
c6953be1 | 540 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
541 | /* Set point first thing, so that undoing this undo |
542 | does not send point back to where it is now. */ | |
350bce56 | 543 | Fgoto_char (car); |
f28f04cc | 544 | Fdelete_region (car, cdr); |
350bce56 | 545 | } |
49be18c9 | 546 | else if (EQ (car, Qapply)) |
6887bce5 | 547 | { |
3419757d | 548 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
549 | struct buffer *save_buffer = current_buffer; |
550 | ||
49be18c9 | 551 | car = Fcar (cdr); |
3419757d | 552 | cdr = Fcdr (cdr); |
49be18c9 KS |
553 | if (INTEGERP (car)) |
554 | { | |
3419757d SM |
555 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
556 | Lisp_Object delta = car; | |
557 | Lisp_Object start = Fcar (cdr); | |
558 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
559 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
560 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
561 | ||
562 | cdr = Fcdr (Fcdr (cdr)); | |
563 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
564 | ||
565 | /* Check that the function did what the entry said it | |
566 | would do. */ | |
567 | if (!EQ (start, Fmarker_position (start_mark)) | |
568 | || (XINT (delta) + XINT (end) | |
569 | != marker_position (end_mark))) | |
570 | error ("Changes to be undone by function different than announced"); | |
571 | Fset_marker (start_mark, Qnil, Qnil); | |
572 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 573 | } |
3419757d SM |
574 | else |
575 | apply1 (car, cdr); | |
a7a39468 KS |
576 | |
577 | if (save_buffer != current_buffer) | |
578 | error ("Undo function switched buffer"); | |
4ac03187 | 579 | did_apply = 1; |
6887bce5 | 580 | } |
38c0d37c | 581 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
582 | { |
583 | /* Element (STRING . POS) means STRING was deleted. */ | |
584 | Lisp_Object membuf; | |
c8a66ab8 | 585 | EMACS_INT pos = XINT (cdr); |
350bce56 RS |
586 | |
587 | membuf = car; | |
588 | if (pos < 0) | |
589 | { | |
590 | if (-pos < BEGV || -pos > ZV) | |
591 | error ("Changes to be undone are outside visible portion of buffer"); | |
592 | SET_PT (-pos); | |
593 | Finsert (1, &membuf); | |
594 | } | |
595 | else | |
596 | { | |
597 | if (pos < BEGV || pos > ZV) | |
598 | error ("Changes to be undone are outside visible portion of buffer"); | |
599 | SET_PT (pos); | |
600 | ||
b2adc409 RS |
601 | /* Now that we record marker adjustments |
602 | (caused by deletion) for undo, | |
603 | we should always insert after markers, | |
604 | so that undoing the marker adjustments | |
605 | put the markers back in the right place. */ | |
606 | Finsert (1, &membuf); | |
350bce56 RS |
607 | SET_PT (pos); |
608 | } | |
c6953be1 | 609 | } |
714bced9 RS |
610 | else if (MARKERP (car) && INTEGERP (cdr)) |
611 | { | |
612 | /* (MARKER . INTEGER) means a marker MARKER | |
613 | was adjusted by INTEGER. */ | |
614 | if (XMARKER (car)->buffer) | |
615 | Fset_marker (car, | |
616 | make_number (marker_position (car) - XINT (cdr)), | |
617 | Fmarker_buffer (car)); | |
618 | } | |
c6953be1 JB |
619 | } |
620 | } | |
621 | arg--; | |
622 | } | |
623 | ||
4ac03187 KS |
624 | |
625 | /* Make sure an apply entry produces at least one undo entry, | |
626 | so the test in `undo' for continuing an undo series | |
627 | will work right. */ | |
628 | if (did_apply | |
4b4deea2 TT |
629 | && EQ (oldlist, BVAR (current_buffer, undo_list))) |
630 | BVAR (current_buffer, undo_list) | |
631 | = Fcons (list3 (Qapply, Qcdr, Qnil), BVAR (current_buffer, undo_list)); | |
4ac03187 | 632 | |
de65837b | 633 | UNGCPRO; |
f87a68b3 | 634 | return unbind_to (count, list); |
c6953be1 | 635 | } |
6887bce5 | 636 | \f |
dfcf069d | 637 | void |
971de7fb | 638 | syms_of_undo (void) |
c6953be1 | 639 | { |
d67b4f80 | 640 | Qinhibit_read_only = intern_c_string ("inhibit-read-only"); |
f87a68b3 RS |
641 | staticpro (&Qinhibit_read_only); |
642 | ||
d67b4f80 | 643 | Qapply = intern_c_string ("apply"); |
49be18c9 KS |
644 | staticpro (&Qapply); |
645 | ||
c58632fc RS |
646 | pending_boundary = Qnil; |
647 | staticpro (&pending_boundary); | |
648 | ||
4591d6cb SM |
649 | last_undo_buffer = NULL; |
650 | last_boundary_buffer = NULL; | |
651 | ||
c6953be1 JB |
652 | defsubr (&Sprimitive_undo); |
653 | defsubr (&Sundo_boundary); | |
137e23ea | 654 | |
29208e82 | 655 | DEFVAR_INT ("undo-limit", undo_limit, |
137e23ea RS |
656 | doc: /* Keep no more undo information once it exceeds this size. |
657 | This limit is applied when garbage collection happens. | |
658 | When a previous command increases the total undo list size past this | |
659 | value, the earlier commands that came before it are forgotten. | |
660 | ||
661 | The size is counted as the number of bytes occupied, | |
662 | which includes both saved text and other data. */); | |
2159bd06 | 663 | undo_limit = 80000; |
137e23ea | 664 | |
29208e82 | 665 | DEFVAR_INT ("undo-strong-limit", undo_strong_limit, |
137e23ea RS |
666 | doc: /* Don't keep more than this much size of undo information. |
667 | This limit is applied when garbage collection happens. | |
668 | When a previous command increases the total undo list size past this | |
669 | value, that command and the earlier commands that came before it are forgotten. | |
670 | However, the most recent buffer-modifying command's undo info | |
671 | is never discarded for this reason. | |
672 | ||
673 | The size is counted as the number of bytes occupied, | |
674 | which includes both saved text and other data. */); | |
2159bd06 | 675 | undo_strong_limit = 120000; |
137e23ea | 676 | |
29208e82 | 677 | DEFVAR_LISP ("undo-outer-limit", Vundo_outer_limit, |
137e23ea RS |
678 | doc: /* Outer limit on size of undo information for one command. |
679 | At garbage collection time, if the current command has produced | |
62d776fd LT |
680 | more than this much undo information, it discards the info and displays |
681 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 682 | |
62d776fd LT |
683 | The size is counted as the number of bytes occupied, which includes |
684 | both saved text and other data. A value of nil means no limit. In | |
685 | this case, accumulating one huge undo entry could make Emacs crash as | |
686 | a result of memory overflow. | |
137e23ea RS |
687 | |
688 | In fact, this calls the function which is the value of | |
689 | `undo-outer-limit-function' with one argument, the size. | |
690 | The text above describes the behavior of the function | |
691 | that variable usually specifies. */); | |
2159bd06 | 692 | Vundo_outer_limit = make_number (12000000); |
137e23ea | 693 | |
29208e82 | 694 | DEFVAR_LISP ("undo-outer-limit-function", Vundo_outer_limit_function, |
137e23ea RS |
695 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. |
696 | This function is called with one argument, the current undo list size | |
697 | for the most recent command (since the last undo boundary). | |
698 | If the function returns t, that means truncation has been fully handled. | |
699 | If it returns nil, the other forms of truncation are done. | |
700 | ||
701 | Garbage collection is inhibited around the call to this function, | |
702 | so it must make sure not to do a lot of consing. */); | |
703 | Vundo_outer_limit_function = Qnil; | |
8abe0f97 | 704 | |
29208e82 | 705 | DEFVAR_BOOL ("undo-inhibit-record-point", undo_inhibit_record_point, |
8abe0f97 MR |
706 | doc: /* Non-nil means do not record `point' in `buffer-undo-list'. */); |
707 | undo_inhibit_record_point = 0; | |
c6953be1 | 708 | } |