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 | 40 | /* Last buffer for which undo information was recorded. */ |
4591d6cb SM |
41 | /* BEWARE: This is not traced by the GC, so never dereference it! */ |
42 | struct buffer *last_undo_buffer; | |
43 | ||
44 | /* Position of point last time we inserted a boundary. */ | |
45 | struct buffer *last_boundary_buffer; | |
46 | EMACS_INT last_boundary_position; | |
c6953be1 | 47 | |
f87a68b3 RS |
48 | Lisp_Object Qinhibit_read_only; |
49 | ||
49be18c9 KS |
50 | /* Marker for function call undo list elements. */ |
51 | ||
52 | Lisp_Object Qapply; | |
53 | ||
c58632fc RS |
54 | /* The first time a command records something for undo. |
55 | it also allocates the undo-boundary object | |
56 | which will be added to the list at the end of the command. | |
57 | This ensures we can't run out of space while trying to make | |
58 | an undo-boundary. */ | |
59 | Lisp_Object pending_boundary; | |
60 | ||
8abe0f97 MR |
61 | /* Nonzero means do not record point in record_point. */ |
62 | ||
63 | int undo_inhibit_record_point; | |
64 | ||
6396140a | 65 | /* Record point as it was at beginning of this command (if necessary) |
8abe0f97 | 66 | and prepare the undo info for recording a change. |
6396140a SM |
67 | PT is the position of point that will naturally occur as a result of the |
68 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 69 | |
6396140a SM |
70 | static void |
71 | record_point (pt) | |
f45bedd4 | 72 | int pt; |
c6953be1 | 73 | { |
6396140a | 74 | int at_boundary; |
bdbe6f28 | 75 | |
4591d6cb | 76 | /* Don't record position of pt when undo_inhibit_record_point holds. */ |
8abe0f97 MR |
77 | if (undo_inhibit_record_point) |
78 | return; | |
79 | ||
c58632fc RS |
80 | /* Allocate a cons cell to be the undo boundary after this command. */ |
81 | if (NILP (pending_boundary)) | |
82 | pending_boundary = Fcons (Qnil, Qnil); | |
83 | ||
4591d6cb | 84 | if (current_buffer != last_undo_buffer) |
c6953be1 | 85 | Fundo_boundary (); |
4591d6cb | 86 | 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 | |
4591d6cb SM |
116 | && current_buffer == last_boundary_buffer |
117 | && last_boundary_position != pt) | |
118 | current_buffer->undo_list | |
119 | = Fcons (make_number (last_boundary_position), current_buffer->undo_list); | |
6396140a SM |
120 | } |
121 | ||
122 | /* Record an insertion that just happened or is about to happen, | |
123 | for LENGTH characters at position BEG. | |
124 | (It is possible to record an insertion before or after the fact | |
125 | because we don't need to record the contents.) */ | |
126 | ||
127 | void | |
128 | record_insert (beg, length) | |
129 | int beg, length; | |
130 | { | |
131 | Lisp_Object lbeg, lend; | |
132 | ||
133 | if (EQ (current_buffer->undo_list, Qt)) | |
134 | return; | |
135 | ||
136 | record_point (beg); | |
137 | ||
c6953be1 JB |
138 | /* If this is following another insertion and consecutive with it |
139 | in the buffer, combine the two. */ | |
38c0d37c | 140 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
141 | { |
142 | Lisp_Object elt; | |
c1d497be | 143 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 144 | if (CONSP (elt) |
c1d497be KR |
145 | && INTEGERP (XCAR (elt)) |
146 | && INTEGERP (XCDR (elt)) | |
147 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 148 | { |
f3fbd155 | 149 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
150 | return; |
151 | } | |
152 | } | |
153 | ||
53480e99 KH |
154 | XSETFASTINT (lbeg, beg); |
155 | XSETINT (lend, beg + length); | |
213861c7 JB |
156 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
157 | current_buffer->undo_list); | |
c6953be1 JB |
158 | } |
159 | ||
160 | /* Record that a deletion is about to take place, | |
e928d437 | 161 | of the characters in STRING, at location BEG. */ |
c6953be1 | 162 | |
ff1aa840 | 163 | void |
e928d437 RS |
164 | record_delete (beg, string) |
165 | int beg; | |
166 | Lisp_Object string; | |
c6953be1 | 167 | { |
e928d437 | 168 | Lisp_Object sbeg; |
c6953be1 | 169 | |
bdbe6f28 RS |
170 | if (EQ (current_buffer->undo_list, Qt)) |
171 | return; | |
172 | ||
d5db4077 | 173 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 174 | { |
6396140a SM |
175 | XSETINT (sbeg, -beg); |
176 | record_point (PT); | |
cbc1b668 KH |
177 | } |
178 | else | |
6396140a SM |
179 | { |
180 | XSETFASTINT (sbeg, beg); | |
181 | record_point (beg); | |
182 | } | |
350bce56 | 183 | |
c6953be1 | 184 | current_buffer->undo_list |
e928d437 | 185 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
186 | } |
187 | ||
714bced9 RS |
188 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
189 | This is done only when a marker points within text being deleted, | |
190 | because that's the only case where an automatic marker adjustment | |
191 | won't be inverted automatically by undoing the buffer modification. */ | |
192 | ||
ff1aa840 | 193 | void |
714bced9 RS |
194 | record_marker_adjustment (marker, adjustment) |
195 | Lisp_Object marker; | |
196 | int adjustment; | |
197 | { | |
198 | if (EQ (current_buffer->undo_list, Qt)) | |
199 | return; | |
200 | ||
201 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
202 | if (NILP (pending_boundary)) | |
203 | pending_boundary = Fcons (Qnil, Qnil); | |
204 | ||
4591d6cb | 205 | if (current_buffer != last_undo_buffer) |
714bced9 | 206 | Fundo_boundary (); |
4591d6cb | 207 | last_undo_buffer = current_buffer; |
714bced9 RS |
208 | |
209 | current_buffer->undo_list | |
210 | = Fcons (Fcons (marker, make_number (adjustment)), | |
211 | current_buffer->undo_list); | |
212 | } | |
213 | ||
c6953be1 JB |
214 | /* Record that a replacement is about to take place, |
215 | for LENGTH characters at location BEG. | |
e928d437 | 216 | The replacement must not change the number of characters. */ |
c6953be1 | 217 | |
ff1aa840 | 218 | void |
c6953be1 JB |
219 | record_change (beg, length) |
220 | int beg, length; | |
221 | { | |
e928d437 | 222 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
223 | record_insert (beg, length); |
224 | } | |
225 | \f | |
226 | /* Record that an unmodified buffer is about to be changed. | |
227 | Record the file modification date so that when undoing this entry | |
228 | we can tell whether it is obsolete because the file was saved again. */ | |
229 | ||
90dd3e4f | 230 | void |
c6953be1 JB |
231 | record_first_change () |
232 | { | |
233 | Lisp_Object high, low; | |
ad9cdce4 | 234 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
235 | |
236 | if (EQ (current_buffer->undo_list, Qt)) | |
237 | return; | |
238 | ||
4591d6cb | 239 | if (current_buffer != last_undo_buffer) |
0736cafe | 240 | Fundo_boundary (); |
4591d6cb | 241 | last_undo_buffer = current_buffer; |
0736cafe | 242 | |
ad9cdce4 RS |
243 | if (base_buffer->base_buffer) |
244 | base_buffer = base_buffer->base_buffer; | |
245 | ||
246 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
247 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
248 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
249 | } | |
250 | ||
da9319d5 RS |
251 | /* Record a change in property PROP (whose old value was VAL) |
252 | for LENGTH characters starting at position BEG in BUFFER. */ | |
253 | ||
90dd3e4f | 254 | void |
da9319d5 RS |
255 | record_property_change (beg, length, prop, value, buffer) |
256 | int beg, length; | |
257 | Lisp_Object prop, value, buffer; | |
258 | { | |
259 | Lisp_Object lbeg, lend, entry; | |
4591d6cb | 260 | struct buffer *obuf = current_buffer, *buf = XBUFFER (buffer); |
da9319d5 RS |
261 | int boundary = 0; |
262 | ||
4591d6cb | 263 | if (EQ (buf->undo_list, Qt)) |
bdbe6f28 RS |
264 | return; |
265 | ||
c58632fc RS |
266 | /* Allocate a cons cell to be the undo boundary after this command. */ |
267 | if (NILP (pending_boundary)) | |
268 | pending_boundary = Fcons (Qnil, Qnil); | |
269 | ||
4591d6cb | 270 | if (buf != last_undo_buffer) |
da9319d5 | 271 | boundary = 1; |
4591d6cb | 272 | last_undo_buffer = buf; |
da9319d5 | 273 | |
da9319d5 | 274 | /* Switch temporarily to the buffer that was changed. */ |
4591d6cb | 275 | current_buffer = buf; |
da9319d5 RS |
276 | |
277 | if (boundary) | |
278 | Fundo_boundary (); | |
279 | ||
ad9cdce4 | 280 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
281 | record_first_change (); |
282 | ||
552bdbcf KH |
283 | XSETINT (lbeg, beg); |
284 | XSETINT (lend, beg + length); | |
da9319d5 RS |
285 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
286 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
287 | ||
288 | current_buffer = obuf; | |
289 | } | |
290 | ||
c6953be1 | 291 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
292 | doc: /* Mark a boundary between units of undo. |
293 | An undo command will stop at this point, | |
294 | but another undo command will undo to the previous boundary. */) | |
295 | () | |
c6953be1 JB |
296 | { |
297 | Lisp_Object tem; | |
298 | if (EQ (current_buffer->undo_list, Qt)) | |
299 | return Qnil; | |
300 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 301 | if (!NILP (tem)) |
c58632fc RS |
302 | { |
303 | /* One way or another, cons nil onto the front of the undo list. */ | |
304 | if (!NILP (pending_boundary)) | |
305 | { | |
306 | /* If we have preallocated the cons cell to use here, | |
307 | use that one. */ | |
f3fbd155 | 308 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
309 | current_buffer->undo_list = pending_boundary; |
310 | pending_boundary = Qnil; | |
311 | } | |
312 | else | |
313 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
314 | } | |
4591d6cb SM |
315 | last_boundary_position = PT; |
316 | last_boundary_buffer = current_buffer; | |
c6953be1 JB |
317 | return Qnil; |
318 | } | |
319 | ||
320 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
321 | returning the truncated list. How this is done depends on the |
322 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
323 | In some cases this works by calling undo-outer-limit-function. */ | |
324 | ||
325 | void | |
326 | truncate_undo_list (b) | |
327 | struct buffer *b; | |
c6953be1 | 328 | { |
137e23ea | 329 | Lisp_Object list; |
c6953be1 JB |
330 | Lisp_Object prev, next, last_boundary; |
331 | int size_so_far = 0; | |
332 | ||
137e23ea RS |
333 | /* Make sure that calling undo-outer-limit-function |
334 | won't cause another GC. */ | |
335 | int count = inhibit_garbage_collection (); | |
336 | ||
337 | /* Make the buffer current to get its local values of variables such | |
338 | as undo_limit. Also so that Vundo_outer_limit_function can | |
339 | tell which buffer to operate on. */ | |
340 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
341 | set_buffer_internal (b); | |
342 | ||
343 | list = b->undo_list; | |
344 | ||
c6953be1 JB |
345 | prev = Qnil; |
346 | next = list; | |
347 | last_boundary = Qnil; | |
348 | ||
137e23ea | 349 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 350 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
351 | { |
352 | /* Add in the space occupied by this element and its chain link. */ | |
353 | size_so_far += sizeof (struct Lisp_Cons); | |
354 | ||
355 | /* Advance to next element. */ | |
356 | prev = next; | |
c1d497be | 357 | next = XCDR (next); |
c6953be1 | 358 | } |
e3d5ca1e | 359 | |
137e23ea RS |
360 | /* Always preserve at least the most recent undo record |
361 | unless it is really horribly big. | |
362 | ||
363 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
364 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
365 | ||
c1d497be | 366 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
367 | { |
368 | Lisp_Object elt; | |
c1d497be | 369 | elt = XCAR (next); |
c6953be1 JB |
370 | |
371 | /* Add in the space occupied by this element and its chain link. */ | |
372 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 373 | if (CONSP (elt)) |
c6953be1 JB |
374 | { |
375 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 376 | if (STRINGP (XCAR (elt))) |
c6953be1 | 377 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 378 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
379 | } |
380 | ||
381 | /* Advance to next element. */ | |
382 | prev = next; | |
c1d497be | 383 | next = XCDR (next); |
c6953be1 | 384 | } |
e3d5ca1e | 385 | |
137e23ea RS |
386 | /* If by the first boundary we have already passed undo_outer_limit, |
387 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
388 | if (INTEGERP (Vundo_outer_limit) |
389 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
390 | && !NILP (Vundo_outer_limit_function)) |
391 | { | |
4591d6cb SM |
392 | Lisp_Object tem; |
393 | struct buffer *temp = last_undo_buffer; | |
137e23ea RS |
394 | |
395 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
396 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
397 | if (! NILP (tem)) | |
137e23ea RS |
398 | { |
399 | /* The function is responsible for making | |
400 | any desired changes in buffer-undo-list. */ | |
401 | unbind_to (count, Qnil); | |
402 | return; | |
403 | } | |
404 | /* That function probably used the minibuffer, and if so, that | |
405 | changed last_undo_buffer. Change it back so that we don't | |
406 | force next change to make an undo boundary here. */ | |
407 | last_undo_buffer = temp; | |
408 | } | |
409 | ||
38c0d37c | 410 | if (CONSP (next)) |
c6953be1 JB |
411 | last_boundary = prev; |
412 | ||
137e23ea | 413 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 414 | while (CONSP (next)) |
c6953be1 JB |
415 | { |
416 | Lisp_Object elt; | |
c1d497be | 417 | elt = XCAR (next); |
c6953be1 JB |
418 | |
419 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 420 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 421 | tells us to truncate after it. If its size pushes past |
137e23ea | 422 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 423 | if (NILP (elt)) |
c6953be1 | 424 | { |
137e23ea | 425 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
426 | break; |
427 | last_boundary = prev; | |
137e23ea | 428 | if (size_so_far > undo_limit) |
c6953be1 JB |
429 | break; |
430 | } | |
431 | ||
432 | /* Add in the space occupied by this element and its chain link. */ | |
433 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 434 | if (CONSP (elt)) |
c6953be1 JB |
435 | { |
436 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 437 | if (STRINGP (XCAR (elt))) |
c6953be1 | 438 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 439 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
440 | } |
441 | ||
442 | /* Advance to next element. */ | |
443 | prev = next; | |
c1d497be | 444 | next = XCDR (next); |
c6953be1 JB |
445 | } |
446 | ||
447 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 448 | if (NILP (next)) |
137e23ea | 449 | ; |
c6953be1 | 450 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
451 | else if (!NILP (last_boundary)) |
452 | XSETCDR (last_boundary, Qnil); | |
453 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 454 | else |
137e23ea RS |
455 | b->undo_list = Qnil; |
456 | ||
457 | unbind_to (count, Qnil); | |
c6953be1 JB |
458 | } |
459 | \f | |
460 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
461 | doc: /* Undo N records from the front of the list LIST. |
462 | Return what remains of the list. */) | |
463 | (n, list) | |
063fb61f | 464 | Lisp_Object n, list; |
c6953be1 | 465 | { |
de65837b KH |
466 | struct gcpro gcpro1, gcpro2; |
467 | Lisp_Object next; | |
331379bf | 468 | int count = SPECPDL_INDEX (); |
de65837b | 469 | register int arg; |
4ac03187 KS |
470 | Lisp_Object oldlist; |
471 | int did_apply = 0; | |
177c0ea7 | 472 | |
c6953be1 JB |
473 | #if 0 /* This is a good feature, but would make undo-start |
474 | unable to do what is expected. */ | |
475 | Lisp_Object tem; | |
476 | ||
477 | /* If the head of the list is a boundary, it is the boundary | |
478 | preceding this command. Get rid of it and don't count it. */ | |
479 | tem = Fcar (list); | |
265a9e55 | 480 | if (NILP (tem)) |
c6953be1 JB |
481 | list = Fcdr (list); |
482 | #endif | |
483 | ||
b7826503 | 484 | CHECK_NUMBER (n); |
de65837b KH |
485 | arg = XINT (n); |
486 | next = Qnil; | |
487 | GCPRO2 (next, list); | |
4ac03187 KS |
488 | /* I don't think we need to gcpro oldlist, as we use it only |
489 | to check for EQ. ++kfs */ | |
de65837b | 490 | |
38d56be3 GM |
491 | /* In a writable buffer, enable undoing read-only text that is so |
492 | because of text properties. */ | |
493 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
494 | specbind (Qinhibit_read_only, Qt); |
495 | ||
8c757fd7 GM |
496 | /* Don't let `intangible' properties interfere with undo. */ |
497 | specbind (Qinhibit_point_motion_hooks, Qt); | |
498 | ||
4ac03187 KS |
499 | oldlist = current_buffer->undo_list; |
500 | ||
c6953be1 JB |
501 | while (arg > 0) |
502 | { | |
c3b09bbf | 503 | while (CONSP (list)) |
c6953be1 | 504 | { |
c3b09bbf SM |
505 | next = XCAR (list); |
506 | list = XCDR (list); | |
350bce56 | 507 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 508 | if (NILP (next)) |
c6953be1 | 509 | break; |
350bce56 | 510 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 511 | if (INTEGERP (next)) |
350bce56 | 512 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 513 | else if (CONSP (next)) |
c6953be1 | 514 | { |
350bce56 RS |
515 | Lisp_Object car, cdr; |
516 | ||
c3b09bbf SM |
517 | car = XCAR (next); |
518 | cdr = XCDR (next); | |
350bce56 | 519 | if (EQ (car, Qt)) |
c6953be1 | 520 | { |
350bce56 RS |
521 | /* Element (t high . low) records previous modtime. */ |
522 | Lisp_Object high, low; | |
523 | int mod_time; | |
ad9cdce4 | 524 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
525 | |
526 | high = Fcar (cdr); | |
527 | low = Fcdr (cdr); | |
d8552b2f | 528 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
529 | |
530 | if (current_buffer->base_buffer) | |
531 | base_buffer = current_buffer->base_buffer; | |
532 | ||
350bce56 RS |
533 | /* If this records an obsolete save |
534 | (not matching the actual disk file) | |
535 | then don't mark unmodified. */ | |
ad9cdce4 | 536 | if (mod_time != base_buffer->modtime) |
103dcb38 | 537 | continue; |
e6dd6080 | 538 | #ifdef CLASH_DETECTION |
350bce56 | 539 | Funlock_buffer (); |
e6dd6080 | 540 | #endif /* CLASH_DETECTION */ |
350bce56 | 541 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 542 | } |
d8552b2f | 543 | else if (EQ (car, Qnil)) |
da9319d5 | 544 | { |
6887bce5 | 545 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
546 | Lisp_Object beg, end, prop, val; |
547 | ||
548 | prop = Fcar (cdr); | |
549 | cdr = Fcdr (cdr); | |
550 | val = Fcar (cdr); | |
551 | cdr = Fcdr (cdr); | |
552 | beg = Fcar (cdr); | |
553 | end = Fcdr (cdr); | |
554 | ||
9e568684 CY |
555 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
556 | error ("Changes to be undone are outside visible portion of buffer"); | |
da9319d5 RS |
557 | Fput_text_property (beg, end, prop, val, Qnil); |
558 | } | |
38c0d37c | 559 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 560 | { |
350bce56 | 561 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
562 | |
563 | if (XINT (car) < BEGV | |
564 | || XINT (cdr) > ZV) | |
c6953be1 | 565 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
566 | /* Set point first thing, so that undoing this undo |
567 | does not send point back to where it is now. */ | |
350bce56 | 568 | Fgoto_char (car); |
f28f04cc | 569 | Fdelete_region (car, cdr); |
350bce56 | 570 | } |
49be18c9 | 571 | else if (EQ (car, Qapply)) |
6887bce5 | 572 | { |
3419757d | 573 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
574 | struct buffer *save_buffer = current_buffer; |
575 | ||
49be18c9 | 576 | car = Fcar (cdr); |
3419757d | 577 | cdr = Fcdr (cdr); |
49be18c9 KS |
578 | if (INTEGERP (car)) |
579 | { | |
3419757d SM |
580 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
581 | Lisp_Object delta = car; | |
582 | Lisp_Object start = Fcar (cdr); | |
583 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
584 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
585 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
586 | ||
587 | cdr = Fcdr (Fcdr (cdr)); | |
588 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
589 | ||
590 | /* Check that the function did what the entry said it | |
591 | would do. */ | |
592 | if (!EQ (start, Fmarker_position (start_mark)) | |
593 | || (XINT (delta) + XINT (end) | |
594 | != marker_position (end_mark))) | |
595 | error ("Changes to be undone by function different than announced"); | |
596 | Fset_marker (start_mark, Qnil, Qnil); | |
597 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 598 | } |
3419757d SM |
599 | else |
600 | apply1 (car, cdr); | |
a7a39468 KS |
601 | |
602 | if (save_buffer != current_buffer) | |
603 | error ("Undo function switched buffer"); | |
4ac03187 | 604 | did_apply = 1; |
6887bce5 | 605 | } |
38c0d37c | 606 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
607 | { |
608 | /* Element (STRING . POS) means STRING was deleted. */ | |
609 | Lisp_Object membuf; | |
610 | int pos = XINT (cdr); | |
611 | ||
612 | membuf = car; | |
613 | if (pos < 0) | |
614 | { | |
615 | if (-pos < BEGV || -pos > ZV) | |
616 | error ("Changes to be undone are outside visible portion of buffer"); | |
617 | SET_PT (-pos); | |
618 | Finsert (1, &membuf); | |
619 | } | |
620 | else | |
621 | { | |
622 | if (pos < BEGV || pos > ZV) | |
623 | error ("Changes to be undone are outside visible portion of buffer"); | |
624 | SET_PT (pos); | |
625 | ||
b2adc409 RS |
626 | /* Now that we record marker adjustments |
627 | (caused by deletion) for undo, | |
628 | we should always insert after markers, | |
629 | so that undoing the marker adjustments | |
630 | put the markers back in the right place. */ | |
631 | Finsert (1, &membuf); | |
350bce56 RS |
632 | SET_PT (pos); |
633 | } | |
c6953be1 | 634 | } |
714bced9 RS |
635 | else if (MARKERP (car) && INTEGERP (cdr)) |
636 | { | |
637 | /* (MARKER . INTEGER) means a marker MARKER | |
638 | was adjusted by INTEGER. */ | |
639 | if (XMARKER (car)->buffer) | |
640 | Fset_marker (car, | |
641 | make_number (marker_position (car) - XINT (cdr)), | |
642 | Fmarker_buffer (car)); | |
643 | } | |
c6953be1 JB |
644 | } |
645 | } | |
646 | arg--; | |
647 | } | |
648 | ||
4ac03187 KS |
649 | |
650 | /* Make sure an apply entry produces at least one undo entry, | |
651 | so the test in `undo' for continuing an undo series | |
652 | will work right. */ | |
653 | if (did_apply | |
654 | && EQ (oldlist, current_buffer->undo_list)) | |
655 | current_buffer->undo_list | |
656 | = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list); | |
657 | ||
de65837b | 658 | UNGCPRO; |
f87a68b3 | 659 | return unbind_to (count, list); |
c6953be1 | 660 | } |
6887bce5 | 661 | \f |
dfcf069d | 662 | void |
c6953be1 JB |
663 | syms_of_undo () |
664 | { | |
f87a68b3 RS |
665 | Qinhibit_read_only = intern ("inhibit-read-only"); |
666 | staticpro (&Qinhibit_read_only); | |
667 | ||
49be18c9 KS |
668 | Qapply = intern ("apply"); |
669 | staticpro (&Qapply); | |
670 | ||
c58632fc RS |
671 | pending_boundary = Qnil; |
672 | staticpro (&pending_boundary); | |
673 | ||
4591d6cb SM |
674 | last_undo_buffer = NULL; |
675 | last_boundary_buffer = NULL; | |
676 | ||
c6953be1 JB |
677 | defsubr (&Sprimitive_undo); |
678 | defsubr (&Sundo_boundary); | |
137e23ea RS |
679 | |
680 | DEFVAR_INT ("undo-limit", &undo_limit, | |
681 | doc: /* Keep no more undo information once it exceeds this size. | |
682 | This limit is applied when garbage collection happens. | |
683 | When a previous command increases the total undo list size past this | |
684 | value, the earlier commands that came before it are forgotten. | |
685 | ||
686 | The size is counted as the number of bytes occupied, | |
687 | which includes both saved text and other data. */); | |
688 | undo_limit = 20000; | |
689 | ||
690 | DEFVAR_INT ("undo-strong-limit", &undo_strong_limit, | |
691 | doc: /* Don't keep more than this much size of undo information. | |
692 | This limit is applied when garbage collection happens. | |
693 | When a previous command increases the total undo list size past this | |
694 | value, that command and the earlier commands that came before it are forgotten. | |
695 | However, the most recent buffer-modifying command's undo info | |
696 | is never discarded for this reason. | |
697 | ||
698 | The size is counted as the number of bytes occupied, | |
699 | which includes both saved text and other data. */); | |
700 | undo_strong_limit = 30000; | |
701 | ||
81c1cf71 | 702 | DEFVAR_LISP ("undo-outer-limit", &Vundo_outer_limit, |
137e23ea RS |
703 | doc: /* Outer limit on size of undo information for one command. |
704 | At garbage collection time, if the current command has produced | |
62d776fd LT |
705 | more than this much undo information, it discards the info and displays |
706 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 707 | |
62d776fd LT |
708 | The size is counted as the number of bytes occupied, which includes |
709 | both saved text and other data. A value of nil means no limit. In | |
710 | this case, accumulating one huge undo entry could make Emacs crash as | |
711 | a result of memory overflow. | |
137e23ea RS |
712 | |
713 | In fact, this calls the function which is the value of | |
714 | `undo-outer-limit-function' with one argument, the size. | |
715 | The text above describes the behavior of the function | |
716 | that variable usually specifies. */); | |
6de38aa3 | 717 | Vundo_outer_limit = make_number (3000000); |
137e23ea RS |
718 | |
719 | DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function, | |
720 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. | |
721 | This function is called with one argument, the current undo list size | |
722 | for the most recent command (since the last undo boundary). | |
723 | If the function returns t, that means truncation has been fully handled. | |
724 | If it returns nil, the other forms of truncation are done. | |
725 | ||
726 | Garbage collection is inhibited around the call to this function, | |
727 | so it must make sure not to do a lot of consing. */); | |
728 | Vundo_outer_limit_function = Qnil; | |
8abe0f97 MR |
729 | |
730 | DEFVAR_BOOL ("undo-inhibit-record-point", &undo_inhibit_record_point, | |
731 | doc: /* Non-nil means do not record `point' in `buffer-undo-list'. */); | |
732 | undo_inhibit_record_point = 0; | |
c6953be1 | 733 | } |
ab5796a9 MB |
734 | |
735 | /* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a | |
736 | (do not change this comment) */ |