Commit | Line | Data |
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c6953be1 | 1 | /* undo handling for GNU Emacs. |
392e96d4 | 2 | Copyright (C) 1990, 1993, 1994, 2000 Free Software Foundation, Inc. |
c6953be1 JB |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
3b7ad313 EN |
6 | GNU Emacs is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
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 | |
17 | along with GNU Emacs; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
c6953be1 JB |
20 | |
21 | ||
18160b98 | 22 | #include <config.h> |
c6953be1 JB |
23 | #include "lisp.h" |
24 | #include "buffer.h" | |
4e665715 | 25 | #include "commands.h" |
c6953be1 | 26 | |
137e23ea RS |
27 | /* Limits controlling how much undo information to keep. */ |
28 | ||
29 | EMACS_INT undo_limit; | |
30 | EMACS_INT undo_strong_limit; | |
31 | EMACS_INT undo_outer_limit; | |
32 | ||
33 | /* Function to call when undo_outer_limit is exceeded. */ | |
34 | ||
35 | Lisp_Object Vundo_outer_limit_function; | |
36 | ||
c6953be1 JB |
37 | /* Last buffer for which undo information was recorded. */ |
38 | Lisp_Object last_undo_buffer; | |
39 | ||
f87a68b3 RS |
40 | Lisp_Object Qinhibit_read_only; |
41 | ||
c58632fc RS |
42 | /* The first time a command records something for undo. |
43 | it also allocates the undo-boundary object | |
44 | which will be added to the list at the end of the command. | |
45 | This ensures we can't run out of space while trying to make | |
46 | an undo-boundary. */ | |
47 | Lisp_Object pending_boundary; | |
48 | ||
6396140a SM |
49 | /* Record point as it was at beginning of this command (if necessary) |
50 | And prepare the undo info for recording a change. | |
51 | PT is the position of point that will naturally occur as a result of the | |
52 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 53 | |
6396140a SM |
54 | static void |
55 | record_point (pt) | |
f45bedd4 | 56 | int pt; |
c6953be1 | 57 | { |
6396140a | 58 | int at_boundary; |
bdbe6f28 | 59 | |
c58632fc RS |
60 | /* Allocate a cons cell to be the undo boundary after this command. */ |
61 | if (NILP (pending_boundary)) | |
62 | pending_boundary = Fcons (Qnil, Qnil); | |
63 | ||
8801a864 KR |
64 | if (!BUFFERP (last_undo_buffer) |
65 | || current_buffer != XBUFFER (last_undo_buffer)) | |
c6953be1 | 66 | Fundo_boundary (); |
552bdbcf | 67 | XSETBUFFER (last_undo_buffer, current_buffer); |
c6953be1 | 68 | |
6396140a SM |
69 | if (CONSP (current_buffer->undo_list)) |
70 | { | |
71 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
72 | marker adjustment before undo boundary. */ | |
73 | ||
74 | Lisp_Object tail = current_buffer->undo_list, elt; | |
75 | ||
76 | while (1) | |
77 | { | |
78 | if (NILP (tail)) | |
79 | elt = Qnil; | |
80 | else | |
81 | elt = XCAR (tail); | |
82 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
83 | break; | |
84 | tail = XCDR (tail); | |
85 | } | |
86 | at_boundary = NILP (elt); | |
87 | } | |
88 | else | |
89 | at_boundary = 1; | |
90 | ||
ad9cdce4 | 91 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
92 | record_first_change (); |
93 | ||
177c0ea7 | 94 | /* If we are just after an undo boundary, and |
6396140a SM |
95 | point wasn't at start of deleted range, record where it was. */ |
96 | if (at_boundary | |
97 | && last_point_position != pt | |
98 | /* If we're called from batch mode, this could be nil. */ | |
99 | && BUFFERP (last_point_position_buffer) | |
100 | && current_buffer == XBUFFER (last_point_position_buffer)) | |
101 | current_buffer->undo_list | |
102 | = Fcons (make_number (last_point_position), current_buffer->undo_list); | |
103 | } | |
104 | ||
105 | /* Record an insertion that just happened or is about to happen, | |
106 | for LENGTH characters at position BEG. | |
107 | (It is possible to record an insertion before or after the fact | |
108 | because we don't need to record the contents.) */ | |
109 | ||
110 | void | |
111 | record_insert (beg, length) | |
112 | int beg, length; | |
113 | { | |
114 | Lisp_Object lbeg, lend; | |
115 | ||
116 | if (EQ (current_buffer->undo_list, Qt)) | |
117 | return; | |
118 | ||
119 | record_point (beg); | |
120 | ||
c6953be1 JB |
121 | /* If this is following another insertion and consecutive with it |
122 | in the buffer, combine the two. */ | |
38c0d37c | 123 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
124 | { |
125 | Lisp_Object elt; | |
c1d497be | 126 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 127 | if (CONSP (elt) |
c1d497be KR |
128 | && INTEGERP (XCAR (elt)) |
129 | && INTEGERP (XCDR (elt)) | |
130 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 131 | { |
f3fbd155 | 132 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
133 | return; |
134 | } | |
135 | } | |
136 | ||
53480e99 KH |
137 | XSETFASTINT (lbeg, beg); |
138 | XSETINT (lend, beg + length); | |
213861c7 JB |
139 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
140 | current_buffer->undo_list); | |
c6953be1 JB |
141 | } |
142 | ||
143 | /* Record that a deletion is about to take place, | |
e928d437 | 144 | of the characters in STRING, at location BEG. */ |
c6953be1 | 145 | |
ff1aa840 | 146 | void |
e928d437 RS |
147 | record_delete (beg, string) |
148 | int beg; | |
149 | Lisp_Object string; | |
c6953be1 | 150 | { |
e928d437 | 151 | Lisp_Object sbeg; |
c6953be1 | 152 | |
bdbe6f28 RS |
153 | if (EQ (current_buffer->undo_list, Qt)) |
154 | return; | |
155 | ||
d5db4077 | 156 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 157 | { |
6396140a SM |
158 | XSETINT (sbeg, -beg); |
159 | record_point (PT); | |
cbc1b668 KH |
160 | } |
161 | else | |
6396140a SM |
162 | { |
163 | XSETFASTINT (sbeg, beg); | |
164 | record_point (beg); | |
165 | } | |
350bce56 | 166 | |
c6953be1 | 167 | current_buffer->undo_list |
e928d437 | 168 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
169 | } |
170 | ||
714bced9 RS |
171 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
172 | This is done only when a marker points within text being deleted, | |
173 | because that's the only case where an automatic marker adjustment | |
174 | won't be inverted automatically by undoing the buffer modification. */ | |
175 | ||
ff1aa840 | 176 | void |
714bced9 RS |
177 | record_marker_adjustment (marker, adjustment) |
178 | Lisp_Object marker; | |
179 | int adjustment; | |
180 | { | |
181 | if (EQ (current_buffer->undo_list, Qt)) | |
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 | ||
177c0ea7 | 188 | if (!BUFFERP (last_undo_buffer) |
2f33f38a | 189 | || current_buffer != XBUFFER (last_undo_buffer)) |
714bced9 RS |
190 | Fundo_boundary (); |
191 | XSETBUFFER (last_undo_buffer, current_buffer); | |
192 | ||
193 | current_buffer->undo_list | |
194 | = Fcons (Fcons (marker, make_number (adjustment)), | |
195 | current_buffer->undo_list); | |
196 | } | |
197 | ||
c6953be1 JB |
198 | /* Record that a replacement is about to take place, |
199 | for LENGTH characters at location BEG. | |
e928d437 | 200 | The replacement must not change the number of characters. */ |
c6953be1 | 201 | |
ff1aa840 | 202 | void |
c6953be1 JB |
203 | record_change (beg, length) |
204 | int beg, length; | |
205 | { | |
e928d437 | 206 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
207 | record_insert (beg, length); |
208 | } | |
209 | \f | |
210 | /* Record that an unmodified buffer is about to be changed. | |
211 | Record the file modification date so that when undoing this entry | |
212 | we can tell whether it is obsolete because the file was saved again. */ | |
213 | ||
90dd3e4f | 214 | void |
c6953be1 JB |
215 | record_first_change () |
216 | { | |
217 | Lisp_Object high, low; | |
ad9cdce4 | 218 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
219 | |
220 | if (EQ (current_buffer->undo_list, Qt)) | |
221 | return; | |
222 | ||
2f33f38a GM |
223 | if (!BUFFERP (last_undo_buffer) |
224 | || current_buffer != XBUFFER (last_undo_buffer)) | |
0736cafe | 225 | Fundo_boundary (); |
552bdbcf | 226 | XSETBUFFER (last_undo_buffer, current_buffer); |
0736cafe | 227 | |
ad9cdce4 RS |
228 | if (base_buffer->base_buffer) |
229 | base_buffer = base_buffer->base_buffer; | |
230 | ||
231 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
232 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
233 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
234 | } | |
235 | ||
da9319d5 RS |
236 | /* Record a change in property PROP (whose old value was VAL) |
237 | for LENGTH characters starting at position BEG in BUFFER. */ | |
238 | ||
90dd3e4f | 239 | void |
da9319d5 RS |
240 | record_property_change (beg, length, prop, value, buffer) |
241 | int beg, length; | |
242 | Lisp_Object prop, value, buffer; | |
243 | { | |
244 | Lisp_Object lbeg, lend, entry; | |
245 | struct buffer *obuf = current_buffer; | |
246 | int boundary = 0; | |
247 | ||
0736cafe | 248 | if (EQ (XBUFFER (buffer)->undo_list, Qt)) |
bdbe6f28 RS |
249 | return; |
250 | ||
c58632fc RS |
251 | /* Allocate a cons cell to be the undo boundary after this command. */ |
252 | if (NILP (pending_boundary)) | |
253 | pending_boundary = Fcons (Qnil, Qnil); | |
254 | ||
da9319d5 RS |
255 | if (!EQ (buffer, last_undo_buffer)) |
256 | boundary = 1; | |
257 | last_undo_buffer = buffer; | |
258 | ||
da9319d5 RS |
259 | /* Switch temporarily to the buffer that was changed. */ |
260 | current_buffer = XBUFFER (buffer); | |
261 | ||
262 | if (boundary) | |
263 | Fundo_boundary (); | |
264 | ||
ad9cdce4 | 265 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
266 | record_first_change (); |
267 | ||
552bdbcf KH |
268 | XSETINT (lbeg, beg); |
269 | XSETINT (lend, beg + length); | |
da9319d5 RS |
270 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
271 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
272 | ||
273 | current_buffer = obuf; | |
274 | } | |
275 | ||
c6953be1 | 276 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
277 | doc: /* Mark a boundary between units of undo. |
278 | An undo command will stop at this point, | |
279 | but another undo command will undo to the previous boundary. */) | |
280 | () | |
c6953be1 JB |
281 | { |
282 | Lisp_Object tem; | |
283 | if (EQ (current_buffer->undo_list, Qt)) | |
284 | return Qnil; | |
285 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 286 | if (!NILP (tem)) |
c58632fc RS |
287 | { |
288 | /* One way or another, cons nil onto the front of the undo list. */ | |
289 | if (!NILP (pending_boundary)) | |
290 | { | |
291 | /* If we have preallocated the cons cell to use here, | |
292 | use that one. */ | |
f3fbd155 | 293 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
294 | current_buffer->undo_list = pending_boundary; |
295 | pending_boundary = Qnil; | |
296 | } | |
297 | else | |
298 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
299 | } | |
c6953be1 JB |
300 | return Qnil; |
301 | } | |
302 | ||
303 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
304 | returning the truncated list. How this is done depends on the |
305 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
306 | In some cases this works by calling undo-outer-limit-function. */ | |
307 | ||
308 | void | |
309 | truncate_undo_list (b) | |
310 | struct buffer *b; | |
c6953be1 | 311 | { |
137e23ea | 312 | Lisp_Object list; |
c6953be1 JB |
313 | Lisp_Object prev, next, last_boundary; |
314 | int size_so_far = 0; | |
315 | ||
137e23ea RS |
316 | /* Make sure that calling undo-outer-limit-function |
317 | won't cause another GC. */ | |
318 | int count = inhibit_garbage_collection (); | |
319 | ||
320 | /* Make the buffer current to get its local values of variables such | |
321 | as undo_limit. Also so that Vundo_outer_limit_function can | |
322 | tell which buffer to operate on. */ | |
323 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
324 | set_buffer_internal (b); | |
325 | ||
326 | list = b->undo_list; | |
327 | ||
c6953be1 JB |
328 | prev = Qnil; |
329 | next = list; | |
330 | last_boundary = Qnil; | |
331 | ||
137e23ea | 332 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 333 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
334 | { |
335 | /* Add in the space occupied by this element and its chain link. */ | |
336 | size_so_far += sizeof (struct Lisp_Cons); | |
337 | ||
338 | /* Advance to next element. */ | |
339 | prev = next; | |
c1d497be | 340 | next = XCDR (next); |
c6953be1 | 341 | } |
e3d5ca1e | 342 | |
137e23ea RS |
343 | /* Always preserve at least the most recent undo record |
344 | unless it is really horribly big. | |
345 | ||
346 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
347 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
348 | ||
c1d497be | 349 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
350 | { |
351 | Lisp_Object elt; | |
c1d497be | 352 | elt = XCAR (next); |
c6953be1 JB |
353 | |
354 | /* Add in the space occupied by this element and its chain link. */ | |
355 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 356 | if (CONSP (elt)) |
c6953be1 JB |
357 | { |
358 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 359 | if (STRINGP (XCAR (elt))) |
c6953be1 | 360 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 361 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
362 | } |
363 | ||
364 | /* Advance to next element. */ | |
365 | prev = next; | |
c1d497be | 366 | next = XCDR (next); |
c6953be1 | 367 | } |
e3d5ca1e | 368 | |
137e23ea RS |
369 | /* If by the first boundary we have already passed undo_outer_limit, |
370 | we're heading for memory full, so offer to clear out the list. */ | |
371 | if (size_so_far > undo_outer_limit | |
372 | && !NILP (Vundo_outer_limit_function)) | |
373 | { | |
374 | Lisp_Object temp = last_undo_buffer; | |
375 | ||
376 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
377 | if (! NILP (call1 (Vundo_outer_limit_function, | |
378 | make_number (size_so_far)))) | |
379 | { | |
380 | /* The function is responsible for making | |
381 | any desired changes in buffer-undo-list. */ | |
382 | unbind_to (count, Qnil); | |
383 | return; | |
384 | } | |
385 | /* That function probably used the minibuffer, and if so, that | |
386 | changed last_undo_buffer. Change it back so that we don't | |
387 | force next change to make an undo boundary here. */ | |
388 | last_undo_buffer = temp; | |
389 | } | |
390 | ||
38c0d37c | 391 | if (CONSP (next)) |
c6953be1 JB |
392 | last_boundary = prev; |
393 | ||
137e23ea | 394 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 395 | while (CONSP (next)) |
c6953be1 JB |
396 | { |
397 | Lisp_Object elt; | |
c1d497be | 398 | elt = XCAR (next); |
c6953be1 JB |
399 | |
400 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 401 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 402 | tells us to truncate after it. If its size pushes past |
137e23ea | 403 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 404 | if (NILP (elt)) |
c6953be1 | 405 | { |
137e23ea | 406 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
407 | break; |
408 | last_boundary = prev; | |
137e23ea | 409 | if (size_so_far > undo_limit) |
c6953be1 JB |
410 | break; |
411 | } | |
412 | ||
413 | /* Add in the space occupied by this element and its chain link. */ | |
414 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 415 | if (CONSP (elt)) |
c6953be1 JB |
416 | { |
417 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 418 | if (STRINGP (XCAR (elt))) |
c6953be1 | 419 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 420 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
421 | } |
422 | ||
423 | /* Advance to next element. */ | |
424 | prev = next; | |
c1d497be | 425 | next = XCDR (next); |
c6953be1 JB |
426 | } |
427 | ||
428 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 429 | if (NILP (next)) |
137e23ea | 430 | ; |
c6953be1 | 431 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
432 | else if (!NILP (last_boundary)) |
433 | XSETCDR (last_boundary, Qnil); | |
434 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 435 | else |
137e23ea RS |
436 | b->undo_list = Qnil; |
437 | ||
438 | unbind_to (count, Qnil); | |
c6953be1 JB |
439 | } |
440 | \f | |
441 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
442 | doc: /* Undo N records from the front of the list LIST. |
443 | Return what remains of the list. */) | |
444 | (n, list) | |
063fb61f | 445 | Lisp_Object n, list; |
c6953be1 | 446 | { |
de65837b KH |
447 | struct gcpro gcpro1, gcpro2; |
448 | Lisp_Object next; | |
331379bf | 449 | int count = SPECPDL_INDEX (); |
de65837b | 450 | register int arg; |
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); | |
467 | ||
38d56be3 GM |
468 | /* In a writable buffer, enable undoing read-only text that is so |
469 | because of text properties. */ | |
470 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
471 | specbind (Qinhibit_read_only, Qt); |
472 | ||
8c757fd7 GM |
473 | /* Don't let `intangible' properties interfere with undo. */ |
474 | specbind (Qinhibit_point_motion_hooks, Qt); | |
475 | ||
c6953be1 JB |
476 | while (arg > 0) |
477 | { | |
c3b09bbf | 478 | while (CONSP (list)) |
c6953be1 | 479 | { |
c3b09bbf SM |
480 | next = XCAR (list); |
481 | list = XCDR (list); | |
350bce56 | 482 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 483 | if (NILP (next)) |
c6953be1 | 484 | break; |
350bce56 | 485 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 486 | if (INTEGERP (next)) |
350bce56 | 487 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 488 | else if (CONSP (next)) |
c6953be1 | 489 | { |
350bce56 RS |
490 | Lisp_Object car, cdr; |
491 | ||
c3b09bbf SM |
492 | car = XCAR (next); |
493 | cdr = XCDR (next); | |
350bce56 | 494 | if (EQ (car, Qt)) |
c6953be1 | 495 | { |
350bce56 RS |
496 | /* Element (t high . low) records previous modtime. */ |
497 | Lisp_Object high, low; | |
498 | int mod_time; | |
ad9cdce4 | 499 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
500 | |
501 | high = Fcar (cdr); | |
502 | low = Fcdr (cdr); | |
d8552b2f | 503 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
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 | { |
d8552b2f | 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 | ||
530 | Fput_text_property (beg, end, prop, val, Qnil); | |
531 | } | |
38c0d37c | 532 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 533 | { |
350bce56 | 534 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
535 | |
536 | if (XINT (car) < BEGV | |
537 | || XINT (cdr) > ZV) | |
c6953be1 | 538 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
539 | /* Set point first thing, so that undoing this undo |
540 | does not send point back to where it is now. */ | |
350bce56 | 541 | Fgoto_char (car); |
f28f04cc | 542 | Fdelete_region (car, cdr); |
350bce56 | 543 | } |
38c0d37c | 544 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
545 | { |
546 | /* Element (STRING . POS) means STRING was deleted. */ | |
547 | Lisp_Object membuf; | |
548 | int pos = XINT (cdr); | |
549 | ||
550 | membuf = car; | |
551 | if (pos < 0) | |
552 | { | |
553 | if (-pos < BEGV || -pos > ZV) | |
554 | error ("Changes to be undone are outside visible portion of buffer"); | |
555 | SET_PT (-pos); | |
556 | Finsert (1, &membuf); | |
557 | } | |
558 | else | |
559 | { | |
560 | if (pos < BEGV || pos > ZV) | |
561 | error ("Changes to be undone are outside visible portion of buffer"); | |
562 | SET_PT (pos); | |
563 | ||
b2adc409 RS |
564 | /* Now that we record marker adjustments |
565 | (caused by deletion) for undo, | |
566 | we should always insert after markers, | |
567 | so that undoing the marker adjustments | |
568 | put the markers back in the right place. */ | |
569 | Finsert (1, &membuf); | |
350bce56 RS |
570 | SET_PT (pos); |
571 | } | |
c6953be1 | 572 | } |
714bced9 RS |
573 | else if (MARKERP (car) && INTEGERP (cdr)) |
574 | { | |
575 | /* (MARKER . INTEGER) means a marker MARKER | |
576 | was adjusted by INTEGER. */ | |
577 | if (XMARKER (car)->buffer) | |
578 | Fset_marker (car, | |
579 | make_number (marker_position (car) - XINT (cdr)), | |
580 | Fmarker_buffer (car)); | |
581 | } | |
c6953be1 JB |
582 | } |
583 | } | |
584 | arg--; | |
585 | } | |
586 | ||
de65837b | 587 | UNGCPRO; |
f87a68b3 | 588 | return unbind_to (count, list); |
c6953be1 JB |
589 | } |
590 | ||
dfcf069d | 591 | void |
c6953be1 JB |
592 | syms_of_undo () |
593 | { | |
f87a68b3 RS |
594 | Qinhibit_read_only = intern ("inhibit-read-only"); |
595 | staticpro (&Qinhibit_read_only); | |
596 | ||
c58632fc RS |
597 | pending_boundary = Qnil; |
598 | staticpro (&pending_boundary); | |
599 | ||
c6953be1 JB |
600 | defsubr (&Sprimitive_undo); |
601 | defsubr (&Sundo_boundary); | |
137e23ea RS |
602 | |
603 | DEFVAR_INT ("undo-limit", &undo_limit, | |
604 | doc: /* Keep no more undo information once it exceeds this size. | |
605 | This limit is applied when garbage collection happens. | |
606 | When a previous command increases the total undo list size past this | |
607 | value, the earlier commands that came before it are forgotten. | |
608 | ||
609 | The size is counted as the number of bytes occupied, | |
610 | which includes both saved text and other data. */); | |
611 | undo_limit = 20000; | |
612 | ||
613 | DEFVAR_INT ("undo-strong-limit", &undo_strong_limit, | |
614 | doc: /* Don't keep more than this much size of undo information. | |
615 | This limit is applied when garbage collection happens. | |
616 | When a previous command increases the total undo list size past this | |
617 | value, that command and the earlier commands that came before it are forgotten. | |
618 | However, the most recent buffer-modifying command's undo info | |
619 | is never discarded for this reason. | |
620 | ||
621 | The size is counted as the number of bytes occupied, | |
622 | which includes both saved text and other data. */); | |
623 | undo_strong_limit = 30000; | |
624 | ||
625 | DEFVAR_INT ("undo-outer-limit", &undo_outer_limit, | |
626 | doc: /* Outer limit on size of undo information for one command. | |
627 | At garbage collection time, if the current command has produced | |
628 | more than this much undo information, it asks you whether to delete | |
629 | the information. This is a last-ditch limit to prevent memory overflow. | |
630 | ||
631 | The size is counted as the number of bytes occupied, | |
632 | which includes both saved text and other data. | |
633 | ||
634 | In fact, this calls the function which is the value of | |
635 | `undo-outer-limit-function' with one argument, the size. | |
636 | The text above describes the behavior of the function | |
637 | that variable usually specifies. */); | |
638 | undo_outer_limit = 300000; | |
639 | ||
640 | DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function, | |
641 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. | |
642 | This function is called with one argument, the current undo list size | |
643 | for the most recent command (since the last undo boundary). | |
644 | If the function returns t, that means truncation has been fully handled. | |
645 | If it returns nil, the other forms of truncation are done. | |
646 | ||
647 | Garbage collection is inhibited around the call to this function, | |
648 | so it must make sure not to do a lot of consing. */); | |
649 | Vundo_outer_limit_function = Qnil; | |
c6953be1 | 650 | } |
ab5796a9 MB |
651 | |
652 | /* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a | |
653 | (do not change this comment) */ |