Commit | Line | Data |
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c6953be1 | 1 | /* undo handling for GNU Emacs. |
429ab54e | 2 | Copyright (C) 1990, 1993, 1994, 2000, 2001, 2002, 2003, 2004, |
8cabe764 | 3 | 2005, 2006, 2007, 2008 Free Software Foundation, Inc. |
c6953be1 JB |
4 | |
5 | This file is part of GNU Emacs. | |
6 | ||
3b7ad313 EN |
7 | GNU Emacs is free software; you can redistribute it and/or modify |
8 | it under the terms of the GNU General Public License as published by | |
684d6f5b | 9 | the Free Software Foundation; either version 3, or (at your option) |
3b7ad313 EN |
10 | any later version. |
11 | ||
c6953be1 | 12 | GNU Emacs is distributed in the hope that it will be useful, |
3b7ad313 EN |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU Emacs; see the file COPYING. If not, write to | |
4fc5845f LK |
19 | the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
20 | Boston, MA 02110-1301, USA. */ | |
c6953be1 JB |
21 | |
22 | ||
18160b98 | 23 | #include <config.h> |
c6953be1 JB |
24 | #include "lisp.h" |
25 | #include "buffer.h" | |
4e665715 | 26 | #include "commands.h" |
91e25f5e | 27 | #include "window.h" |
c6953be1 | 28 | |
137e23ea RS |
29 | /* Limits controlling how much undo information to keep. */ |
30 | ||
31 | EMACS_INT undo_limit; | |
32 | EMACS_INT undo_strong_limit; | |
81c1cf71 RS |
33 | |
34 | Lisp_Object Vundo_outer_limit; | |
137e23ea RS |
35 | |
36 | /* Function to call when undo_outer_limit is exceeded. */ | |
37 | ||
38 | Lisp_Object Vundo_outer_limit_function; | |
39 | ||
c6953be1 JB |
40 | /* Last buffer for which undo information was recorded. */ |
41 | Lisp_Object last_undo_buffer; | |
42 | ||
f87a68b3 RS |
43 | Lisp_Object Qinhibit_read_only; |
44 | ||
49be18c9 KS |
45 | /* Marker for function call undo list elements. */ |
46 | ||
47 | Lisp_Object Qapply; | |
48 | ||
c58632fc RS |
49 | /* The first time a command records something for undo. |
50 | it also allocates the undo-boundary object | |
51 | which will be added to the list at the end of the command. | |
52 | This ensures we can't run out of space while trying to make | |
53 | an undo-boundary. */ | |
54 | Lisp_Object pending_boundary; | |
55 | ||
8abe0f97 MR |
56 | /* Nonzero means do not record point in record_point. */ |
57 | ||
58 | int undo_inhibit_record_point; | |
59 | ||
6396140a | 60 | /* Record point as it was at beginning of this command (if necessary) |
8abe0f97 | 61 | and prepare the undo info for recording a change. |
6396140a SM |
62 | PT is the position of point that will naturally occur as a result of the |
63 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 64 | |
6396140a SM |
65 | static void |
66 | record_point (pt) | |
f45bedd4 | 67 | int pt; |
c6953be1 | 68 | { |
6396140a | 69 | int at_boundary; |
bdbe6f28 | 70 | |
8abe0f97 MR |
71 | /* Don't record position of pt when undo_inhibit_record_point holds. |
72 | Needed to avoid inserting a position record in buffer-undo-list | |
73 | when last_point_position has not been set up correctly by | |
74 | command_loop_1, for example, when running a repeat-repeat-char | |
75 | event. */ | |
76 | if (undo_inhibit_record_point) | |
77 | return; | |
78 | ||
c58632fc RS |
79 | /* Allocate a cons cell to be the undo boundary after this command. */ |
80 | if (NILP (pending_boundary)) | |
81 | pending_boundary = Fcons (Qnil, Qnil); | |
82 | ||
8801a864 KR |
83 | if (!BUFFERP (last_undo_buffer) |
84 | || current_buffer != XBUFFER (last_undo_buffer)) | |
c6953be1 | 85 | Fundo_boundary (); |
552bdbcf | 86 | XSETBUFFER (last_undo_buffer, current_buffer); |
c6953be1 | 87 | |
6396140a SM |
88 | if (CONSP (current_buffer->undo_list)) |
89 | { | |
90 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
91 | marker adjustment before undo boundary. */ | |
92 | ||
93 | Lisp_Object tail = current_buffer->undo_list, elt; | |
94 | ||
95 | while (1) | |
96 | { | |
97 | if (NILP (tail)) | |
98 | elt = Qnil; | |
99 | else | |
100 | elt = XCAR (tail); | |
101 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
102 | break; | |
103 | tail = XCDR (tail); | |
104 | } | |
105 | at_boundary = NILP (elt); | |
106 | } | |
107 | else | |
108 | at_boundary = 1; | |
109 | ||
ad9cdce4 | 110 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
111 | record_first_change (); |
112 | ||
177c0ea7 | 113 | /* If we are just after an undo boundary, and |
6396140a SM |
114 | point wasn't at start of deleted range, record where it was. */ |
115 | if (at_boundary | |
6396140a | 116 | && BUFFERP (last_point_position_buffer) |
91e25f5e | 117 | /* If we're called from batch mode, this could be nil. */ |
6396140a | 118 | && current_buffer == XBUFFER (last_point_position_buffer)) |
91e25f5e RS |
119 | { |
120 | /* If we have switched windows, use the point value | |
121 | from the window we are in. */ | |
122 | if (! EQ (last_point_position_window, selected_window)) | |
123 | last_point_position = marker_position (XWINDOW (selected_window)->pointm); | |
124 | ||
125 | if (last_point_position != pt) | |
126 | current_buffer->undo_list | |
127 | = Fcons (make_number (last_point_position), current_buffer->undo_list); | |
128 | } | |
6396140a SM |
129 | } |
130 | ||
131 | /* Record an insertion that just happened or is about to happen, | |
132 | for LENGTH characters at position BEG. | |
133 | (It is possible to record an insertion before or after the fact | |
134 | because we don't need to record the contents.) */ | |
135 | ||
136 | void | |
137 | record_insert (beg, length) | |
138 | int beg, length; | |
139 | { | |
140 | Lisp_Object lbeg, lend; | |
141 | ||
142 | if (EQ (current_buffer->undo_list, Qt)) | |
143 | return; | |
144 | ||
145 | record_point (beg); | |
146 | ||
c6953be1 JB |
147 | /* If this is following another insertion and consecutive with it |
148 | in the buffer, combine the two. */ | |
38c0d37c | 149 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
150 | { |
151 | Lisp_Object elt; | |
c1d497be | 152 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 153 | if (CONSP (elt) |
c1d497be KR |
154 | && INTEGERP (XCAR (elt)) |
155 | && INTEGERP (XCDR (elt)) | |
156 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 157 | { |
f3fbd155 | 158 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
159 | return; |
160 | } | |
161 | } | |
162 | ||
53480e99 KH |
163 | XSETFASTINT (lbeg, beg); |
164 | XSETINT (lend, beg + length); | |
213861c7 JB |
165 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
166 | current_buffer->undo_list); | |
c6953be1 JB |
167 | } |
168 | ||
169 | /* Record that a deletion is about to take place, | |
e928d437 | 170 | of the characters in STRING, at location BEG. */ |
c6953be1 | 171 | |
ff1aa840 | 172 | void |
e928d437 RS |
173 | record_delete (beg, string) |
174 | int beg; | |
175 | Lisp_Object string; | |
c6953be1 | 176 | { |
e928d437 | 177 | Lisp_Object sbeg; |
c6953be1 | 178 | |
bdbe6f28 RS |
179 | if (EQ (current_buffer->undo_list, Qt)) |
180 | return; | |
181 | ||
d5db4077 | 182 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 183 | { |
6396140a SM |
184 | XSETINT (sbeg, -beg); |
185 | record_point (PT); | |
cbc1b668 KH |
186 | } |
187 | else | |
6396140a SM |
188 | { |
189 | XSETFASTINT (sbeg, beg); | |
190 | record_point (beg); | |
191 | } | |
350bce56 | 192 | |
c6953be1 | 193 | current_buffer->undo_list |
e928d437 | 194 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
195 | } |
196 | ||
714bced9 RS |
197 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
198 | This is done only when a marker points within text being deleted, | |
199 | because that's the only case where an automatic marker adjustment | |
200 | won't be inverted automatically by undoing the buffer modification. */ | |
201 | ||
ff1aa840 | 202 | void |
714bced9 RS |
203 | record_marker_adjustment (marker, adjustment) |
204 | Lisp_Object marker; | |
205 | int adjustment; | |
206 | { | |
207 | if (EQ (current_buffer->undo_list, Qt)) | |
208 | return; | |
209 | ||
210 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
211 | if (NILP (pending_boundary)) | |
212 | pending_boundary = Fcons (Qnil, Qnil); | |
213 | ||
177c0ea7 | 214 | if (!BUFFERP (last_undo_buffer) |
2f33f38a | 215 | || current_buffer != XBUFFER (last_undo_buffer)) |
714bced9 RS |
216 | Fundo_boundary (); |
217 | XSETBUFFER (last_undo_buffer, current_buffer); | |
218 | ||
219 | current_buffer->undo_list | |
220 | = Fcons (Fcons (marker, make_number (adjustment)), | |
221 | current_buffer->undo_list); | |
222 | } | |
223 | ||
c6953be1 JB |
224 | /* Record that a replacement is about to take place, |
225 | for LENGTH characters at location BEG. | |
e928d437 | 226 | The replacement must not change the number of characters. */ |
c6953be1 | 227 | |
ff1aa840 | 228 | void |
c6953be1 JB |
229 | record_change (beg, length) |
230 | int beg, length; | |
231 | { | |
e928d437 | 232 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
233 | record_insert (beg, length); |
234 | } | |
235 | \f | |
236 | /* Record that an unmodified buffer is about to be changed. | |
237 | Record the file modification date so that when undoing this entry | |
238 | we can tell whether it is obsolete because the file was saved again. */ | |
239 | ||
90dd3e4f | 240 | void |
c6953be1 JB |
241 | record_first_change () |
242 | { | |
243 | Lisp_Object high, low; | |
ad9cdce4 | 244 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
245 | |
246 | if (EQ (current_buffer->undo_list, Qt)) | |
247 | return; | |
248 | ||
2f33f38a GM |
249 | if (!BUFFERP (last_undo_buffer) |
250 | || current_buffer != XBUFFER (last_undo_buffer)) | |
0736cafe | 251 | Fundo_boundary (); |
552bdbcf | 252 | XSETBUFFER (last_undo_buffer, current_buffer); |
0736cafe | 253 | |
ad9cdce4 RS |
254 | if (base_buffer->base_buffer) |
255 | base_buffer = base_buffer->base_buffer; | |
256 | ||
257 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
258 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
259 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
260 | } | |
261 | ||
da9319d5 RS |
262 | /* Record a change in property PROP (whose old value was VAL) |
263 | for LENGTH characters starting at position BEG in BUFFER. */ | |
264 | ||
90dd3e4f | 265 | void |
da9319d5 RS |
266 | record_property_change (beg, length, prop, value, buffer) |
267 | int beg, length; | |
268 | Lisp_Object prop, value, buffer; | |
269 | { | |
270 | Lisp_Object lbeg, lend, entry; | |
271 | struct buffer *obuf = current_buffer; | |
272 | int boundary = 0; | |
273 | ||
0736cafe | 274 | if (EQ (XBUFFER (buffer)->undo_list, Qt)) |
bdbe6f28 RS |
275 | return; |
276 | ||
c58632fc RS |
277 | /* Allocate a cons cell to be the undo boundary after this command. */ |
278 | if (NILP (pending_boundary)) | |
279 | pending_boundary = Fcons (Qnil, Qnil); | |
280 | ||
da9319d5 RS |
281 | if (!EQ (buffer, last_undo_buffer)) |
282 | boundary = 1; | |
283 | last_undo_buffer = buffer; | |
284 | ||
da9319d5 RS |
285 | /* Switch temporarily to the buffer that was changed. */ |
286 | current_buffer = XBUFFER (buffer); | |
287 | ||
288 | if (boundary) | |
289 | Fundo_boundary (); | |
290 | ||
ad9cdce4 | 291 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
292 | record_first_change (); |
293 | ||
552bdbcf KH |
294 | XSETINT (lbeg, beg); |
295 | XSETINT (lend, beg + length); | |
da9319d5 RS |
296 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
297 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
298 | ||
299 | current_buffer = obuf; | |
300 | } | |
301 | ||
c6953be1 | 302 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
303 | doc: /* Mark a boundary between units of undo. |
304 | An undo command will stop at this point, | |
305 | but another undo command will undo to the previous boundary. */) | |
306 | () | |
c6953be1 JB |
307 | { |
308 | Lisp_Object tem; | |
309 | if (EQ (current_buffer->undo_list, Qt)) | |
310 | return Qnil; | |
311 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 312 | if (!NILP (tem)) |
c58632fc RS |
313 | { |
314 | /* One way or another, cons nil onto the front of the undo list. */ | |
315 | if (!NILP (pending_boundary)) | |
316 | { | |
317 | /* If we have preallocated the cons cell to use here, | |
318 | use that one. */ | |
f3fbd155 | 319 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
320 | current_buffer->undo_list = pending_boundary; |
321 | pending_boundary = Qnil; | |
322 | } | |
323 | else | |
324 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
325 | } | |
c6953be1 JB |
326 | return Qnil; |
327 | } | |
328 | ||
329 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
330 | returning the truncated list. How this is done depends on the |
331 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
332 | In some cases this works by calling undo-outer-limit-function. */ | |
333 | ||
334 | void | |
335 | truncate_undo_list (b) | |
336 | struct buffer *b; | |
c6953be1 | 337 | { |
137e23ea | 338 | Lisp_Object list; |
c6953be1 JB |
339 | Lisp_Object prev, next, last_boundary; |
340 | int size_so_far = 0; | |
341 | ||
137e23ea RS |
342 | /* Make sure that calling undo-outer-limit-function |
343 | won't cause another GC. */ | |
344 | int count = inhibit_garbage_collection (); | |
345 | ||
346 | /* Make the buffer current to get its local values of variables such | |
347 | as undo_limit. Also so that Vundo_outer_limit_function can | |
348 | tell which buffer to operate on. */ | |
349 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
350 | set_buffer_internal (b); | |
351 | ||
352 | list = b->undo_list; | |
353 | ||
c6953be1 JB |
354 | prev = Qnil; |
355 | next = list; | |
356 | last_boundary = Qnil; | |
357 | ||
137e23ea | 358 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 359 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
360 | { |
361 | /* Add in the space occupied by this element and its chain link. */ | |
362 | size_so_far += sizeof (struct Lisp_Cons); | |
363 | ||
364 | /* Advance to next element. */ | |
365 | prev = next; | |
c1d497be | 366 | next = XCDR (next); |
c6953be1 | 367 | } |
e3d5ca1e | 368 | |
137e23ea RS |
369 | /* Always preserve at least the most recent undo record |
370 | unless it is really horribly big. | |
371 | ||
372 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
373 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
374 | ||
c1d497be | 375 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
376 | { |
377 | Lisp_Object elt; | |
c1d497be | 378 | elt = XCAR (next); |
c6953be1 JB |
379 | |
380 | /* Add in the space occupied by this element and its chain link. */ | |
381 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 382 | if (CONSP (elt)) |
c6953be1 JB |
383 | { |
384 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 385 | if (STRINGP (XCAR (elt))) |
c6953be1 | 386 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 387 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
388 | } |
389 | ||
390 | /* Advance to next element. */ | |
391 | prev = next; | |
c1d497be | 392 | next = XCDR (next); |
c6953be1 | 393 | } |
e3d5ca1e | 394 | |
137e23ea RS |
395 | /* If by the first boundary we have already passed undo_outer_limit, |
396 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
397 | if (INTEGERP (Vundo_outer_limit) |
398 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
399 | && !NILP (Vundo_outer_limit_function)) |
400 | { | |
88fde92a | 401 | Lisp_Object temp = last_undo_buffer, tem; |
137e23ea RS |
402 | |
403 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
404 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
405 | if (! NILP (tem)) | |
137e23ea RS |
406 | { |
407 | /* The function is responsible for making | |
408 | any desired changes in buffer-undo-list. */ | |
409 | unbind_to (count, Qnil); | |
410 | return; | |
411 | } | |
412 | /* That function probably used the minibuffer, and if so, that | |
413 | changed last_undo_buffer. Change it back so that we don't | |
414 | force next change to make an undo boundary here. */ | |
415 | last_undo_buffer = temp; | |
416 | } | |
417 | ||
38c0d37c | 418 | if (CONSP (next)) |
c6953be1 JB |
419 | last_boundary = prev; |
420 | ||
137e23ea | 421 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 422 | while (CONSP (next)) |
c6953be1 JB |
423 | { |
424 | Lisp_Object elt; | |
c1d497be | 425 | elt = XCAR (next); |
c6953be1 JB |
426 | |
427 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 428 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 429 | tells us to truncate after it. If its size pushes past |
137e23ea | 430 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 431 | if (NILP (elt)) |
c6953be1 | 432 | { |
137e23ea | 433 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
434 | break; |
435 | last_boundary = prev; | |
137e23ea | 436 | if (size_so_far > undo_limit) |
c6953be1 JB |
437 | break; |
438 | } | |
439 | ||
440 | /* Add in the space occupied by this element and its chain link. */ | |
441 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 442 | if (CONSP (elt)) |
c6953be1 JB |
443 | { |
444 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 445 | if (STRINGP (XCAR (elt))) |
c6953be1 | 446 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 447 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
448 | } |
449 | ||
450 | /* Advance to next element. */ | |
451 | prev = next; | |
c1d497be | 452 | next = XCDR (next); |
c6953be1 JB |
453 | } |
454 | ||
455 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 456 | if (NILP (next)) |
137e23ea | 457 | ; |
c6953be1 | 458 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
459 | else if (!NILP (last_boundary)) |
460 | XSETCDR (last_boundary, Qnil); | |
461 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 462 | else |
137e23ea RS |
463 | b->undo_list = Qnil; |
464 | ||
465 | unbind_to (count, Qnil); | |
c6953be1 JB |
466 | } |
467 | \f | |
468 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
469 | doc: /* Undo N records from the front of the list LIST. |
470 | Return what remains of the list. */) | |
471 | (n, list) | |
063fb61f | 472 | Lisp_Object n, list; |
c6953be1 | 473 | { |
de65837b KH |
474 | struct gcpro gcpro1, gcpro2; |
475 | Lisp_Object next; | |
331379bf | 476 | int count = SPECPDL_INDEX (); |
de65837b | 477 | register int arg; |
4ac03187 KS |
478 | Lisp_Object oldlist; |
479 | int did_apply = 0; | |
177c0ea7 | 480 | |
c6953be1 JB |
481 | #if 0 /* This is a good feature, but would make undo-start |
482 | unable to do what is expected. */ | |
483 | Lisp_Object tem; | |
484 | ||
485 | /* If the head of the list is a boundary, it is the boundary | |
486 | preceding this command. Get rid of it and don't count it. */ | |
487 | tem = Fcar (list); | |
265a9e55 | 488 | if (NILP (tem)) |
c6953be1 JB |
489 | list = Fcdr (list); |
490 | #endif | |
491 | ||
b7826503 | 492 | CHECK_NUMBER (n); |
de65837b KH |
493 | arg = XINT (n); |
494 | next = Qnil; | |
495 | GCPRO2 (next, list); | |
4ac03187 KS |
496 | /* I don't think we need to gcpro oldlist, as we use it only |
497 | to check for EQ. ++kfs */ | |
de65837b | 498 | |
38d56be3 GM |
499 | /* In a writable buffer, enable undoing read-only text that is so |
500 | because of text properties. */ | |
501 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
502 | specbind (Qinhibit_read_only, Qt); |
503 | ||
8c757fd7 GM |
504 | /* Don't let `intangible' properties interfere with undo. */ |
505 | specbind (Qinhibit_point_motion_hooks, Qt); | |
506 | ||
4ac03187 KS |
507 | oldlist = current_buffer->undo_list; |
508 | ||
c6953be1 JB |
509 | while (arg > 0) |
510 | { | |
c3b09bbf | 511 | while (CONSP (list)) |
c6953be1 | 512 | { |
c3b09bbf SM |
513 | next = XCAR (list); |
514 | list = XCDR (list); | |
350bce56 | 515 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 516 | if (NILP (next)) |
c6953be1 | 517 | break; |
350bce56 | 518 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 519 | if (INTEGERP (next)) |
350bce56 | 520 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 521 | else if (CONSP (next)) |
c6953be1 | 522 | { |
350bce56 RS |
523 | Lisp_Object car, cdr; |
524 | ||
c3b09bbf SM |
525 | car = XCAR (next); |
526 | cdr = XCDR (next); | |
350bce56 | 527 | if (EQ (car, Qt)) |
c6953be1 | 528 | { |
350bce56 RS |
529 | /* Element (t high . low) records previous modtime. */ |
530 | Lisp_Object high, low; | |
531 | int mod_time; | |
ad9cdce4 | 532 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
533 | |
534 | high = Fcar (cdr); | |
535 | low = Fcdr (cdr); | |
d8552b2f | 536 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
537 | |
538 | if (current_buffer->base_buffer) | |
539 | base_buffer = current_buffer->base_buffer; | |
540 | ||
350bce56 RS |
541 | /* If this records an obsolete save |
542 | (not matching the actual disk file) | |
543 | then don't mark unmodified. */ | |
ad9cdce4 | 544 | if (mod_time != base_buffer->modtime) |
103dcb38 | 545 | continue; |
e6dd6080 | 546 | #ifdef CLASH_DETECTION |
350bce56 | 547 | Funlock_buffer (); |
e6dd6080 | 548 | #endif /* CLASH_DETECTION */ |
350bce56 | 549 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 550 | } |
d8552b2f | 551 | else if (EQ (car, Qnil)) |
da9319d5 | 552 | { |
6887bce5 | 553 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
554 | Lisp_Object beg, end, prop, val; |
555 | ||
556 | prop = Fcar (cdr); | |
557 | cdr = Fcdr (cdr); | |
558 | val = Fcar (cdr); | |
559 | cdr = Fcdr (cdr); | |
560 | beg = Fcar (cdr); | |
561 | end = Fcdr (cdr); | |
562 | ||
9e568684 CY |
563 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
564 | error ("Changes to be undone are outside visible portion of buffer"); | |
da9319d5 RS |
565 | Fput_text_property (beg, end, prop, val, Qnil); |
566 | } | |
38c0d37c | 567 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 568 | { |
350bce56 | 569 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
570 | |
571 | if (XINT (car) < BEGV | |
572 | || XINT (cdr) > ZV) | |
c6953be1 | 573 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
574 | /* Set point first thing, so that undoing this undo |
575 | does not send point back to where it is now. */ | |
350bce56 | 576 | Fgoto_char (car); |
f28f04cc | 577 | Fdelete_region (car, cdr); |
350bce56 | 578 | } |
49be18c9 | 579 | else if (EQ (car, Qapply)) |
6887bce5 | 580 | { |
3419757d | 581 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
582 | struct buffer *save_buffer = current_buffer; |
583 | ||
49be18c9 | 584 | car = Fcar (cdr); |
3419757d | 585 | cdr = Fcdr (cdr); |
49be18c9 KS |
586 | if (INTEGERP (car)) |
587 | { | |
3419757d SM |
588 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
589 | Lisp_Object delta = car; | |
590 | Lisp_Object start = Fcar (cdr); | |
591 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
592 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
593 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
594 | ||
595 | cdr = Fcdr (Fcdr (cdr)); | |
596 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
597 | ||
598 | /* Check that the function did what the entry said it | |
599 | would do. */ | |
600 | if (!EQ (start, Fmarker_position (start_mark)) | |
601 | || (XINT (delta) + XINT (end) | |
602 | != marker_position (end_mark))) | |
603 | error ("Changes to be undone by function different than announced"); | |
604 | Fset_marker (start_mark, Qnil, Qnil); | |
605 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 606 | } |
3419757d SM |
607 | else |
608 | apply1 (car, cdr); | |
a7a39468 KS |
609 | |
610 | if (save_buffer != current_buffer) | |
611 | error ("Undo function switched buffer"); | |
4ac03187 | 612 | did_apply = 1; |
6887bce5 | 613 | } |
38c0d37c | 614 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
615 | { |
616 | /* Element (STRING . POS) means STRING was deleted. */ | |
617 | Lisp_Object membuf; | |
618 | int pos = XINT (cdr); | |
619 | ||
620 | membuf = car; | |
621 | if (pos < 0) | |
622 | { | |
623 | if (-pos < BEGV || -pos > ZV) | |
624 | error ("Changes to be undone are outside visible portion of buffer"); | |
625 | SET_PT (-pos); | |
626 | Finsert (1, &membuf); | |
627 | } | |
628 | else | |
629 | { | |
630 | if (pos < BEGV || pos > ZV) | |
631 | error ("Changes to be undone are outside visible portion of buffer"); | |
632 | SET_PT (pos); | |
633 | ||
b2adc409 RS |
634 | /* Now that we record marker adjustments |
635 | (caused by deletion) for undo, | |
636 | we should always insert after markers, | |
637 | so that undoing the marker adjustments | |
638 | put the markers back in the right place. */ | |
639 | Finsert (1, &membuf); | |
350bce56 RS |
640 | SET_PT (pos); |
641 | } | |
c6953be1 | 642 | } |
714bced9 RS |
643 | else if (MARKERP (car) && INTEGERP (cdr)) |
644 | { | |
645 | /* (MARKER . INTEGER) means a marker MARKER | |
646 | was adjusted by INTEGER. */ | |
647 | if (XMARKER (car)->buffer) | |
648 | Fset_marker (car, | |
649 | make_number (marker_position (car) - XINT (cdr)), | |
650 | Fmarker_buffer (car)); | |
651 | } | |
c6953be1 JB |
652 | } |
653 | } | |
654 | arg--; | |
655 | } | |
656 | ||
4ac03187 KS |
657 | |
658 | /* Make sure an apply entry produces at least one undo entry, | |
659 | so the test in `undo' for continuing an undo series | |
660 | will work right. */ | |
661 | if (did_apply | |
662 | && EQ (oldlist, current_buffer->undo_list)) | |
663 | current_buffer->undo_list | |
664 | = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list); | |
665 | ||
de65837b | 666 | UNGCPRO; |
f87a68b3 | 667 | return unbind_to (count, list); |
c6953be1 | 668 | } |
6887bce5 | 669 | \f |
dfcf069d | 670 | void |
c6953be1 JB |
671 | syms_of_undo () |
672 | { | |
f87a68b3 RS |
673 | Qinhibit_read_only = intern ("inhibit-read-only"); |
674 | staticpro (&Qinhibit_read_only); | |
675 | ||
49be18c9 KS |
676 | Qapply = intern ("apply"); |
677 | staticpro (&Qapply); | |
678 | ||
c58632fc RS |
679 | pending_boundary = Qnil; |
680 | staticpro (&pending_boundary); | |
681 | ||
c6953be1 JB |
682 | defsubr (&Sprimitive_undo); |
683 | defsubr (&Sundo_boundary); | |
137e23ea RS |
684 | |
685 | DEFVAR_INT ("undo-limit", &undo_limit, | |
686 | doc: /* Keep no more undo information once it exceeds this size. | |
687 | This limit is applied when garbage collection happens. | |
688 | When a previous command increases the total undo list size past this | |
689 | value, the earlier commands that came before it are forgotten. | |
690 | ||
691 | The size is counted as the number of bytes occupied, | |
692 | which includes both saved text and other data. */); | |
693 | undo_limit = 20000; | |
694 | ||
695 | DEFVAR_INT ("undo-strong-limit", &undo_strong_limit, | |
696 | doc: /* Don't keep more than this much size of undo information. | |
697 | This limit is applied when garbage collection happens. | |
698 | When a previous command increases the total undo list size past this | |
699 | value, that command and the earlier commands that came before it are forgotten. | |
700 | However, the most recent buffer-modifying command's undo info | |
701 | is never discarded for this reason. | |
702 | ||
703 | The size is counted as the number of bytes occupied, | |
704 | which includes both saved text and other data. */); | |
705 | undo_strong_limit = 30000; | |
706 | ||
81c1cf71 | 707 | DEFVAR_LISP ("undo-outer-limit", &Vundo_outer_limit, |
137e23ea RS |
708 | doc: /* Outer limit on size of undo information for one command. |
709 | At garbage collection time, if the current command has produced | |
62d776fd LT |
710 | more than this much undo information, it discards the info and displays |
711 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 712 | |
62d776fd LT |
713 | The size is counted as the number of bytes occupied, which includes |
714 | both saved text and other data. A value of nil means no limit. In | |
715 | this case, accumulating one huge undo entry could make Emacs crash as | |
716 | a result of memory overflow. | |
137e23ea RS |
717 | |
718 | In fact, this calls the function which is the value of | |
719 | `undo-outer-limit-function' with one argument, the size. | |
720 | The text above describes the behavior of the function | |
721 | that variable usually specifies. */); | |
6de38aa3 | 722 | Vundo_outer_limit = make_number (3000000); |
137e23ea RS |
723 | |
724 | DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function, | |
725 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. | |
726 | This function is called with one argument, the current undo list size | |
727 | for the most recent command (since the last undo boundary). | |
728 | If the function returns t, that means truncation has been fully handled. | |
729 | If it returns nil, the other forms of truncation are done. | |
730 | ||
731 | Garbage collection is inhibited around the call to this function, | |
732 | so it must make sure not to do a lot of consing. */); | |
733 | Vundo_outer_limit_function = Qnil; | |
8abe0f97 MR |
734 | |
735 | DEFVAR_BOOL ("undo-inhibit-record-point", &undo_inhibit_record_point, | |
736 | doc: /* Non-nil means do not record `point' in `buffer-undo-list'. */); | |
737 | undo_inhibit_record_point = 0; | |
c6953be1 | 738 | } |
ab5796a9 MB |
739 | |
740 | /* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a | |
741 | (do not change this comment) */ |