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; | |
81c1cf71 RS |
31 | |
32 | Lisp_Object Vundo_outer_limit; | |
137e23ea RS |
33 | |
34 | /* Function to call when undo_outer_limit is exceeded. */ | |
35 | ||
36 | Lisp_Object Vundo_outer_limit_function; | |
37 | ||
c6953be1 JB |
38 | /* Last buffer for which undo information was recorded. */ |
39 | Lisp_Object last_undo_buffer; | |
40 | ||
f87a68b3 RS |
41 | Lisp_Object Qinhibit_read_only; |
42 | ||
49be18c9 KS |
43 | /* Marker for function call undo list elements. */ |
44 | ||
45 | Lisp_Object Qapply; | |
46 | ||
c58632fc RS |
47 | /* The first time a command records something for undo. |
48 | it also allocates the undo-boundary object | |
49 | which will be added to the list at the end of the command. | |
50 | This ensures we can't run out of space while trying to make | |
51 | an undo-boundary. */ | |
52 | Lisp_Object pending_boundary; | |
53 | ||
6396140a SM |
54 | /* Record point as it was at beginning of this command (if necessary) |
55 | And prepare the undo info for recording a change. | |
56 | PT is the position of point that will naturally occur as a result of the | |
57 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 58 | |
6396140a SM |
59 | static void |
60 | record_point (pt) | |
f45bedd4 | 61 | int pt; |
c6953be1 | 62 | { |
6396140a | 63 | int at_boundary; |
bdbe6f28 | 64 | |
c58632fc RS |
65 | /* Allocate a cons cell to be the undo boundary after this command. */ |
66 | if (NILP (pending_boundary)) | |
67 | pending_boundary = Fcons (Qnil, Qnil); | |
68 | ||
8801a864 KR |
69 | if (!BUFFERP (last_undo_buffer) |
70 | || current_buffer != XBUFFER (last_undo_buffer)) | |
c6953be1 | 71 | Fundo_boundary (); |
552bdbcf | 72 | XSETBUFFER (last_undo_buffer, current_buffer); |
c6953be1 | 73 | |
6396140a SM |
74 | if (CONSP (current_buffer->undo_list)) |
75 | { | |
76 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
77 | marker adjustment before undo boundary. */ | |
78 | ||
79 | Lisp_Object tail = current_buffer->undo_list, elt; | |
80 | ||
81 | while (1) | |
82 | { | |
83 | if (NILP (tail)) | |
84 | elt = Qnil; | |
85 | else | |
86 | elt = XCAR (tail); | |
87 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
88 | break; | |
89 | tail = XCDR (tail); | |
90 | } | |
91 | at_boundary = NILP (elt); | |
92 | } | |
93 | else | |
94 | at_boundary = 1; | |
95 | ||
ad9cdce4 | 96 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
97 | record_first_change (); |
98 | ||
177c0ea7 | 99 | /* If we are just after an undo boundary, and |
6396140a SM |
100 | point wasn't at start of deleted range, record where it was. */ |
101 | if (at_boundary | |
102 | && last_point_position != pt | |
103 | /* If we're called from batch mode, this could be nil. */ | |
104 | && BUFFERP (last_point_position_buffer) | |
105 | && current_buffer == XBUFFER (last_point_position_buffer)) | |
106 | current_buffer->undo_list | |
107 | = Fcons (make_number (last_point_position), current_buffer->undo_list); | |
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 | |
116 | record_insert (beg, length) | |
117 | int beg, length; | |
118 | { | |
119 | Lisp_Object lbeg, lend; | |
120 | ||
121 | if (EQ (current_buffer->undo_list, Qt)) | |
122 | return; | |
123 | ||
124 | record_point (beg); | |
125 | ||
c6953be1 JB |
126 | /* If this is following another insertion and consecutive with it |
127 | in the buffer, combine the two. */ | |
38c0d37c | 128 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
129 | { |
130 | Lisp_Object elt; | |
c1d497be | 131 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 132 | if (CONSP (elt) |
c1d497be KR |
133 | && INTEGERP (XCAR (elt)) |
134 | && INTEGERP (XCDR (elt)) | |
135 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 136 | { |
f3fbd155 | 137 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
138 | return; |
139 | } | |
140 | } | |
141 | ||
53480e99 KH |
142 | XSETFASTINT (lbeg, beg); |
143 | XSETINT (lend, beg + length); | |
213861c7 JB |
144 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
145 | current_buffer->undo_list); | |
c6953be1 JB |
146 | } |
147 | ||
148 | /* Record that a deletion is about to take place, | |
e928d437 | 149 | of the characters in STRING, at location BEG. */ |
c6953be1 | 150 | |
ff1aa840 | 151 | void |
e928d437 RS |
152 | record_delete (beg, string) |
153 | int beg; | |
154 | Lisp_Object string; | |
c6953be1 | 155 | { |
e928d437 | 156 | Lisp_Object sbeg; |
c6953be1 | 157 | |
bdbe6f28 RS |
158 | if (EQ (current_buffer->undo_list, Qt)) |
159 | return; | |
160 | ||
d5db4077 | 161 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 162 | { |
6396140a SM |
163 | XSETINT (sbeg, -beg); |
164 | record_point (PT); | |
cbc1b668 KH |
165 | } |
166 | else | |
6396140a SM |
167 | { |
168 | XSETFASTINT (sbeg, beg); | |
169 | record_point (beg); | |
170 | } | |
350bce56 | 171 | |
c6953be1 | 172 | current_buffer->undo_list |
e928d437 | 173 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
174 | } |
175 | ||
714bced9 RS |
176 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
177 | This is done only when a marker points within text being deleted, | |
178 | because that's the only case where an automatic marker adjustment | |
179 | won't be inverted automatically by undoing the buffer modification. */ | |
180 | ||
ff1aa840 | 181 | void |
714bced9 RS |
182 | record_marker_adjustment (marker, adjustment) |
183 | Lisp_Object marker; | |
184 | int adjustment; | |
185 | { | |
186 | if (EQ (current_buffer->undo_list, Qt)) | |
187 | return; | |
188 | ||
189 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
190 | if (NILP (pending_boundary)) | |
191 | pending_boundary = Fcons (Qnil, Qnil); | |
192 | ||
177c0ea7 | 193 | if (!BUFFERP (last_undo_buffer) |
2f33f38a | 194 | || current_buffer != XBUFFER (last_undo_buffer)) |
714bced9 RS |
195 | Fundo_boundary (); |
196 | XSETBUFFER (last_undo_buffer, current_buffer); | |
197 | ||
198 | current_buffer->undo_list | |
199 | = Fcons (Fcons (marker, make_number (adjustment)), | |
200 | current_buffer->undo_list); | |
201 | } | |
202 | ||
c6953be1 JB |
203 | /* Record that a replacement is about to take place, |
204 | for LENGTH characters at location BEG. | |
e928d437 | 205 | The replacement must not change the number of characters. */ |
c6953be1 | 206 | |
ff1aa840 | 207 | void |
c6953be1 JB |
208 | record_change (beg, length) |
209 | int beg, length; | |
210 | { | |
e928d437 | 211 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
212 | record_insert (beg, length); |
213 | } | |
214 | \f | |
215 | /* Record that an unmodified buffer is about to be changed. | |
216 | Record the file modification date so that when undoing this entry | |
217 | we can tell whether it is obsolete because the file was saved again. */ | |
218 | ||
90dd3e4f | 219 | void |
c6953be1 JB |
220 | record_first_change () |
221 | { | |
222 | Lisp_Object high, low; | |
ad9cdce4 | 223 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
224 | |
225 | if (EQ (current_buffer->undo_list, Qt)) | |
226 | return; | |
227 | ||
2f33f38a GM |
228 | if (!BUFFERP (last_undo_buffer) |
229 | || current_buffer != XBUFFER (last_undo_buffer)) | |
0736cafe | 230 | Fundo_boundary (); |
552bdbcf | 231 | XSETBUFFER (last_undo_buffer, current_buffer); |
0736cafe | 232 | |
ad9cdce4 RS |
233 | if (base_buffer->base_buffer) |
234 | base_buffer = base_buffer->base_buffer; | |
235 | ||
236 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
237 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
238 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
239 | } | |
240 | ||
da9319d5 RS |
241 | /* Record a change in property PROP (whose old value was VAL) |
242 | for LENGTH characters starting at position BEG in BUFFER. */ | |
243 | ||
90dd3e4f | 244 | void |
da9319d5 RS |
245 | record_property_change (beg, length, prop, value, buffer) |
246 | int beg, length; | |
247 | Lisp_Object prop, value, buffer; | |
248 | { | |
249 | Lisp_Object lbeg, lend, entry; | |
250 | struct buffer *obuf = current_buffer; | |
251 | int boundary = 0; | |
252 | ||
0736cafe | 253 | if (EQ (XBUFFER (buffer)->undo_list, Qt)) |
bdbe6f28 RS |
254 | return; |
255 | ||
c58632fc RS |
256 | /* Allocate a cons cell to be the undo boundary after this command. */ |
257 | if (NILP (pending_boundary)) | |
258 | pending_boundary = Fcons (Qnil, Qnil); | |
259 | ||
da9319d5 RS |
260 | if (!EQ (buffer, last_undo_buffer)) |
261 | boundary = 1; | |
262 | last_undo_buffer = buffer; | |
263 | ||
da9319d5 RS |
264 | /* Switch temporarily to the buffer that was changed. */ |
265 | current_buffer = XBUFFER (buffer); | |
266 | ||
267 | if (boundary) | |
268 | Fundo_boundary (); | |
269 | ||
ad9cdce4 | 270 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
271 | record_first_change (); |
272 | ||
552bdbcf KH |
273 | XSETINT (lbeg, beg); |
274 | XSETINT (lend, beg + length); | |
da9319d5 RS |
275 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
276 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
277 | ||
278 | current_buffer = obuf; | |
279 | } | |
280 | ||
c6953be1 | 281 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
282 | doc: /* Mark a boundary between units of undo. |
283 | An undo command will stop at this point, | |
284 | but another undo command will undo to the previous boundary. */) | |
285 | () | |
c6953be1 JB |
286 | { |
287 | Lisp_Object tem; | |
288 | if (EQ (current_buffer->undo_list, Qt)) | |
289 | return Qnil; | |
290 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 291 | if (!NILP (tem)) |
c58632fc RS |
292 | { |
293 | /* One way or another, cons nil onto the front of the undo list. */ | |
294 | if (!NILP (pending_boundary)) | |
295 | { | |
296 | /* If we have preallocated the cons cell to use here, | |
297 | use that one. */ | |
f3fbd155 | 298 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
299 | current_buffer->undo_list = pending_boundary; |
300 | pending_boundary = Qnil; | |
301 | } | |
302 | else | |
303 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
304 | } | |
c6953be1 JB |
305 | return Qnil; |
306 | } | |
307 | ||
308 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
309 | returning the truncated list. How this is done depends on the |
310 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
311 | In some cases this works by calling undo-outer-limit-function. */ | |
312 | ||
313 | void | |
314 | truncate_undo_list (b) | |
315 | struct buffer *b; | |
c6953be1 | 316 | { |
137e23ea | 317 | Lisp_Object list; |
c6953be1 JB |
318 | Lisp_Object prev, next, last_boundary; |
319 | int size_so_far = 0; | |
320 | ||
137e23ea RS |
321 | /* Make sure that calling undo-outer-limit-function |
322 | won't cause another GC. */ | |
323 | int count = inhibit_garbage_collection (); | |
324 | ||
325 | /* Make the buffer current to get its local values of variables such | |
326 | as undo_limit. Also so that Vundo_outer_limit_function can | |
327 | tell which buffer to operate on. */ | |
328 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
329 | set_buffer_internal (b); | |
330 | ||
331 | list = b->undo_list; | |
332 | ||
c6953be1 JB |
333 | prev = Qnil; |
334 | next = list; | |
335 | last_boundary = Qnil; | |
336 | ||
137e23ea | 337 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 338 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
339 | { |
340 | /* Add in the space occupied by this element and its chain link. */ | |
341 | size_so_far += sizeof (struct Lisp_Cons); | |
342 | ||
343 | /* Advance to next element. */ | |
344 | prev = next; | |
c1d497be | 345 | next = XCDR (next); |
c6953be1 | 346 | } |
e3d5ca1e | 347 | |
137e23ea RS |
348 | /* Always preserve at least the most recent undo record |
349 | unless it is really horribly big. | |
350 | ||
351 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
352 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
353 | ||
c1d497be | 354 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
355 | { |
356 | Lisp_Object elt; | |
c1d497be | 357 | elt = XCAR (next); |
c6953be1 JB |
358 | |
359 | /* Add in the space occupied by this element and its chain link. */ | |
360 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 361 | if (CONSP (elt)) |
c6953be1 JB |
362 | { |
363 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 364 | if (STRINGP (XCAR (elt))) |
c6953be1 | 365 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 366 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
367 | } |
368 | ||
369 | /* Advance to next element. */ | |
370 | prev = next; | |
c1d497be | 371 | next = XCDR (next); |
c6953be1 | 372 | } |
e3d5ca1e | 373 | |
137e23ea RS |
374 | /* If by the first boundary we have already passed undo_outer_limit, |
375 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
376 | if (INTEGERP (Vundo_outer_limit) |
377 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
378 | && !NILP (Vundo_outer_limit_function)) |
379 | { | |
380 | Lisp_Object temp = last_undo_buffer; | |
381 | ||
382 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
383 | if (! NILP (call1 (Vundo_outer_limit_function, | |
384 | make_number (size_so_far)))) | |
385 | { | |
386 | /* The function is responsible for making | |
387 | any desired changes in buffer-undo-list. */ | |
388 | unbind_to (count, Qnil); | |
389 | return; | |
390 | } | |
391 | /* That function probably used the minibuffer, and if so, that | |
392 | changed last_undo_buffer. Change it back so that we don't | |
393 | force next change to make an undo boundary here. */ | |
394 | last_undo_buffer = temp; | |
395 | } | |
396 | ||
38c0d37c | 397 | if (CONSP (next)) |
c6953be1 JB |
398 | last_boundary = prev; |
399 | ||
137e23ea | 400 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 401 | while (CONSP (next)) |
c6953be1 JB |
402 | { |
403 | Lisp_Object elt; | |
c1d497be | 404 | elt = XCAR (next); |
c6953be1 JB |
405 | |
406 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 407 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 408 | tells us to truncate after it. If its size pushes past |
137e23ea | 409 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 410 | if (NILP (elt)) |
c6953be1 | 411 | { |
137e23ea | 412 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
413 | break; |
414 | last_boundary = prev; | |
137e23ea | 415 | if (size_so_far > undo_limit) |
c6953be1 JB |
416 | break; |
417 | } | |
418 | ||
419 | /* Add in the space occupied by this element and its chain link. */ | |
420 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 421 | if (CONSP (elt)) |
c6953be1 JB |
422 | { |
423 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 424 | if (STRINGP (XCAR (elt))) |
c6953be1 | 425 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 426 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
427 | } |
428 | ||
429 | /* Advance to next element. */ | |
430 | prev = next; | |
c1d497be | 431 | next = XCDR (next); |
c6953be1 JB |
432 | } |
433 | ||
434 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 435 | if (NILP (next)) |
137e23ea | 436 | ; |
c6953be1 | 437 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
438 | else if (!NILP (last_boundary)) |
439 | XSETCDR (last_boundary, Qnil); | |
440 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 441 | else |
137e23ea RS |
442 | b->undo_list = Qnil; |
443 | ||
444 | unbind_to (count, Qnil); | |
c6953be1 JB |
445 | } |
446 | \f | |
447 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
448 | doc: /* Undo N records from the front of the list LIST. |
449 | Return what remains of the list. */) | |
450 | (n, list) | |
063fb61f | 451 | Lisp_Object n, list; |
c6953be1 | 452 | { |
de65837b KH |
453 | struct gcpro gcpro1, gcpro2; |
454 | Lisp_Object next; | |
331379bf | 455 | int count = SPECPDL_INDEX (); |
de65837b | 456 | register int arg; |
177c0ea7 | 457 | |
c6953be1 JB |
458 | #if 0 /* This is a good feature, but would make undo-start |
459 | unable to do what is expected. */ | |
460 | Lisp_Object tem; | |
461 | ||
462 | /* If the head of the list is a boundary, it is the boundary | |
463 | preceding this command. Get rid of it and don't count it. */ | |
464 | tem = Fcar (list); | |
265a9e55 | 465 | if (NILP (tem)) |
c6953be1 JB |
466 | list = Fcdr (list); |
467 | #endif | |
468 | ||
b7826503 | 469 | CHECK_NUMBER (n); |
de65837b KH |
470 | arg = XINT (n); |
471 | next = Qnil; | |
472 | GCPRO2 (next, list); | |
473 | ||
38d56be3 GM |
474 | /* In a writable buffer, enable undoing read-only text that is so |
475 | because of text properties. */ | |
476 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
477 | specbind (Qinhibit_read_only, Qt); |
478 | ||
8c757fd7 GM |
479 | /* Don't let `intangible' properties interfere with undo. */ |
480 | specbind (Qinhibit_point_motion_hooks, Qt); | |
481 | ||
c6953be1 JB |
482 | while (arg > 0) |
483 | { | |
c3b09bbf | 484 | while (CONSP (list)) |
c6953be1 | 485 | { |
c3b09bbf SM |
486 | next = XCAR (list); |
487 | list = XCDR (list); | |
350bce56 | 488 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 489 | if (NILP (next)) |
c6953be1 | 490 | break; |
350bce56 | 491 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 492 | if (INTEGERP (next)) |
350bce56 | 493 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 494 | else if (CONSP (next)) |
c6953be1 | 495 | { |
350bce56 RS |
496 | Lisp_Object car, cdr; |
497 | ||
c3b09bbf SM |
498 | car = XCAR (next); |
499 | cdr = XCDR (next); | |
350bce56 | 500 | if (EQ (car, Qt)) |
c6953be1 | 501 | { |
350bce56 RS |
502 | /* Element (t high . low) records previous modtime. */ |
503 | Lisp_Object high, low; | |
504 | int mod_time; | |
ad9cdce4 | 505 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
506 | |
507 | high = Fcar (cdr); | |
508 | low = Fcdr (cdr); | |
d8552b2f | 509 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
510 | |
511 | if (current_buffer->base_buffer) | |
512 | base_buffer = current_buffer->base_buffer; | |
513 | ||
350bce56 RS |
514 | /* If this records an obsolete save |
515 | (not matching the actual disk file) | |
516 | then don't mark unmodified. */ | |
ad9cdce4 | 517 | if (mod_time != base_buffer->modtime) |
103dcb38 | 518 | continue; |
e6dd6080 | 519 | #ifdef CLASH_DETECTION |
350bce56 | 520 | Funlock_buffer (); |
e6dd6080 | 521 | #endif /* CLASH_DETECTION */ |
350bce56 | 522 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 523 | } |
d8552b2f | 524 | else if (EQ (car, Qnil)) |
da9319d5 | 525 | { |
6887bce5 | 526 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
527 | Lisp_Object beg, end, prop, val; |
528 | ||
529 | prop = Fcar (cdr); | |
530 | cdr = Fcdr (cdr); | |
531 | val = Fcar (cdr); | |
532 | cdr = Fcdr (cdr); | |
533 | beg = Fcar (cdr); | |
534 | end = Fcdr (cdr); | |
535 | ||
536 | Fput_text_property (beg, end, prop, val, Qnil); | |
537 | } | |
38c0d37c | 538 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 539 | { |
350bce56 | 540 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
541 | |
542 | if (XINT (car) < BEGV | |
543 | || XINT (cdr) > ZV) | |
c6953be1 | 544 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
545 | /* Set point first thing, so that undoing this undo |
546 | does not send point back to where it is now. */ | |
350bce56 | 547 | Fgoto_char (car); |
f28f04cc | 548 | Fdelete_region (car, cdr); |
350bce56 | 549 | } |
49be18c9 | 550 | else if (EQ (car, Qapply)) |
6887bce5 RS |
551 | { |
552 | Lisp_Object oldlist = current_buffer->undo_list; | |
49be18c9 KS |
553 | /* Element (apply FUNNAME . ARGS) means call FUNNAME to undo. */ |
554 | car = Fcar (cdr); | |
555 | if (INTEGERP (car)) | |
556 | { | |
557 | /* Long format: (apply DELTA START END FUNNAME . ARGS). */ | |
558 | cdr = Fcdr (Fcdr (Fcdr (cdr))); | |
559 | car = Fcar (cdr); | |
560 | } | |
561 | cdr = Fcdr (cdr); | |
6887bce5 | 562 | apply1 (car, cdr); |
ed71a5cf | 563 | |
6887bce5 RS |
564 | /* Make sure this produces at least one undo entry, |
565 | so the test in `undo' for continuing an undo series | |
566 | will work right. */ | |
567 | if (EQ (oldlist, current_buffer->undo_list)) | |
568 | current_buffer->undo_list | |
ed71a5cf | 569 | = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list); |
6887bce5 | 570 | } |
38c0d37c | 571 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
572 | { |
573 | /* Element (STRING . POS) means STRING was deleted. */ | |
574 | Lisp_Object membuf; | |
575 | int pos = XINT (cdr); | |
576 | ||
577 | membuf = car; | |
578 | if (pos < 0) | |
579 | { | |
580 | if (-pos < BEGV || -pos > ZV) | |
581 | error ("Changes to be undone are outside visible portion of buffer"); | |
582 | SET_PT (-pos); | |
583 | Finsert (1, &membuf); | |
584 | } | |
585 | else | |
586 | { | |
587 | if (pos < BEGV || pos > ZV) | |
588 | error ("Changes to be undone are outside visible portion of buffer"); | |
589 | SET_PT (pos); | |
590 | ||
b2adc409 RS |
591 | /* Now that we record marker adjustments |
592 | (caused by deletion) for undo, | |
593 | we should always insert after markers, | |
594 | so that undoing the marker adjustments | |
595 | put the markers back in the right place. */ | |
596 | Finsert (1, &membuf); | |
350bce56 RS |
597 | SET_PT (pos); |
598 | } | |
c6953be1 | 599 | } |
714bced9 RS |
600 | else if (MARKERP (car) && INTEGERP (cdr)) |
601 | { | |
602 | /* (MARKER . INTEGER) means a marker MARKER | |
603 | was adjusted by INTEGER. */ | |
604 | if (XMARKER (car)->buffer) | |
605 | Fset_marker (car, | |
606 | make_number (marker_position (car) - XINT (cdr)), | |
607 | Fmarker_buffer (car)); | |
608 | } | |
c6953be1 JB |
609 | } |
610 | } | |
611 | arg--; | |
612 | } | |
613 | ||
de65837b | 614 | UNGCPRO; |
f87a68b3 | 615 | return unbind_to (count, list); |
c6953be1 | 616 | } |
6887bce5 | 617 | \f |
dfcf069d | 618 | void |
c6953be1 JB |
619 | syms_of_undo () |
620 | { | |
f87a68b3 RS |
621 | Qinhibit_read_only = intern ("inhibit-read-only"); |
622 | staticpro (&Qinhibit_read_only); | |
623 | ||
49be18c9 KS |
624 | Qapply = intern ("apply"); |
625 | staticpro (&Qapply); | |
626 | ||
c58632fc RS |
627 | pending_boundary = Qnil; |
628 | staticpro (&pending_boundary); | |
629 | ||
c6953be1 JB |
630 | defsubr (&Sprimitive_undo); |
631 | defsubr (&Sundo_boundary); | |
137e23ea RS |
632 | |
633 | DEFVAR_INT ("undo-limit", &undo_limit, | |
634 | doc: /* Keep no more undo information once it exceeds this size. | |
635 | This limit is applied when garbage collection happens. | |
636 | When a previous command increases the total undo list size past this | |
637 | value, the earlier commands that came before it are forgotten. | |
638 | ||
639 | The size is counted as the number of bytes occupied, | |
640 | which includes both saved text and other data. */); | |
641 | undo_limit = 20000; | |
642 | ||
643 | DEFVAR_INT ("undo-strong-limit", &undo_strong_limit, | |
644 | doc: /* Don't keep more than this much size of undo information. | |
645 | This limit is applied when garbage collection happens. | |
646 | When a previous command increases the total undo list size past this | |
647 | value, that command and the earlier commands that came before it are forgotten. | |
648 | However, the most recent buffer-modifying command's undo info | |
649 | is never discarded for this reason. | |
650 | ||
651 | The size is counted as the number of bytes occupied, | |
652 | which includes both saved text and other data. */); | |
653 | undo_strong_limit = 30000; | |
654 | ||
81c1cf71 | 655 | DEFVAR_LISP ("undo-outer-limit", &Vundo_outer_limit, |
137e23ea RS |
656 | doc: /* Outer limit on size of undo information for one command. |
657 | At garbage collection time, if the current command has produced | |
62d776fd LT |
658 | more than this much undo information, it discards the info and displays |
659 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 660 | |
62d776fd LT |
661 | The size is counted as the number of bytes occupied, which includes |
662 | both saved text and other data. A value of nil means no limit. In | |
663 | this case, accumulating one huge undo entry could make Emacs crash as | |
664 | a result of memory overflow. | |
137e23ea RS |
665 | |
666 | In fact, this calls the function which is the value of | |
667 | `undo-outer-limit-function' with one argument, the size. | |
668 | The text above describes the behavior of the function | |
669 | that variable usually specifies. */); | |
6de38aa3 | 670 | Vundo_outer_limit = make_number (3000000); |
137e23ea RS |
671 | |
672 | DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function, | |
673 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. | |
674 | This function is called with one argument, the current undo list size | |
675 | for the most recent command (since the last undo boundary). | |
676 | If the function returns t, that means truncation has been fully handled. | |
677 | If it returns nil, the other forms of truncation are done. | |
678 | ||
679 | Garbage collection is inhibited around the call to this function, | |
680 | so it must make sure not to do a lot of consing. */); | |
681 | Vundo_outer_limit_function = Qnil; | |
c6953be1 | 682 | } |
ab5796a9 MB |
683 | |
684 | /* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a | |
685 | (do not change this comment) */ |