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, |
5df4f04c | 3 | 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
c6953be1 JB |
4 | |
5 | This file is part of GNU Emacs. | |
6 | ||
9ec0b715 | 7 | GNU Emacs is free software: you can redistribute it and/or modify |
3b7ad313 | 8 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
9 | the Free Software Foundation, either version 3 of the License, or |
10 | (at your option) any later version. | |
3b7ad313 | 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 | |
9ec0b715 | 18 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
c6953be1 JB |
19 | |
20 | ||
18160b98 | 21 | #include <config.h> |
d7306fe6 | 22 | #include <setjmp.h> |
c6953be1 JB |
23 | #include "lisp.h" |
24 | #include "buffer.h" | |
4e665715 | 25 | #include "commands.h" |
91e25f5e | 26 | #include "window.h" |
c6953be1 | 27 | |
137e23ea RS |
28 | /* Limits controlling how much undo information to keep. */ |
29 | ||
30 | EMACS_INT undo_limit; | |
31 | EMACS_INT undo_strong_limit; | |
81c1cf71 RS |
32 | |
33 | Lisp_Object Vundo_outer_limit; | |
137e23ea RS |
34 | |
35 | /* Function to call when undo_outer_limit is exceeded. */ | |
36 | ||
37 | Lisp_Object Vundo_outer_limit_function; | |
38 | ||
c6953be1 | 39 | /* Last buffer for which undo information was recorded. */ |
4591d6cb SM |
40 | /* BEWARE: This is not traced by the GC, so never dereference it! */ |
41 | struct buffer *last_undo_buffer; | |
42 | ||
43 | /* Position of point last time we inserted a boundary. */ | |
44 | struct buffer *last_boundary_buffer; | |
45 | EMACS_INT last_boundary_position; | |
c6953be1 | 46 | |
f87a68b3 RS |
47 | Lisp_Object Qinhibit_read_only; |
48 | ||
49be18c9 KS |
49 | /* Marker for function call undo list elements. */ |
50 | ||
51 | Lisp_Object Qapply; | |
52 | ||
c58632fc RS |
53 | /* The first time a command records something for undo. |
54 | it also allocates the undo-boundary object | |
55 | which will be added to the list at the end of the command. | |
56 | This ensures we can't run out of space while trying to make | |
57 | an undo-boundary. */ | |
58 | Lisp_Object pending_boundary; | |
59 | ||
8abe0f97 MR |
60 | /* Nonzero means do not record point in record_point. */ |
61 | ||
62 | int undo_inhibit_record_point; | |
63 | ||
6396140a | 64 | /* Record point as it was at beginning of this command (if necessary) |
8abe0f97 | 65 | and prepare the undo info for recording a change. |
6396140a SM |
66 | PT is the position of point that will naturally occur as a result of the |
67 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 68 | |
6396140a SM |
69 | static void |
70 | record_point (pt) | |
f45bedd4 | 71 | int pt; |
c6953be1 | 72 | { |
6396140a | 73 | int at_boundary; |
bdbe6f28 | 74 | |
4591d6cb | 75 | /* Don't record position of pt when undo_inhibit_record_point holds. */ |
8abe0f97 MR |
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 | ||
3ecc1163 MR |
83 | if ((current_buffer != last_undo_buffer) |
84 | /* Don't call Fundo_boundary for the first change. Otherwise we | |
85 | risk overwriting last_boundary_position in Fundo_boundary with | |
86 | PT of the current buffer and as a consequence not insert an | |
87 | undo boundary because last_boundary_position will equal pt in | |
88 | the test at the end of the present function (Bug#731). */ | |
89 | && (MODIFF > SAVE_MODIFF)) | |
c6953be1 | 90 | Fundo_boundary (); |
4591d6cb | 91 | last_undo_buffer = current_buffer; |
c6953be1 | 92 | |
6396140a SM |
93 | if (CONSP (current_buffer->undo_list)) |
94 | { | |
95 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
96 | marker adjustment before undo boundary. */ | |
97 | ||
98 | Lisp_Object tail = current_buffer->undo_list, elt; | |
99 | ||
100 | while (1) | |
101 | { | |
102 | if (NILP (tail)) | |
103 | elt = Qnil; | |
104 | else | |
105 | elt = XCAR (tail); | |
106 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
107 | break; | |
108 | tail = XCDR (tail); | |
109 | } | |
110 | at_boundary = NILP (elt); | |
111 | } | |
112 | else | |
113 | at_boundary = 1; | |
114 | ||
ad9cdce4 | 115 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
116 | record_first_change (); |
117 | ||
177c0ea7 | 118 | /* If we are just after an undo boundary, and |
6396140a SM |
119 | point wasn't at start of deleted range, record where it was. */ |
120 | if (at_boundary | |
4591d6cb SM |
121 | && current_buffer == last_boundary_buffer |
122 | && last_boundary_position != pt) | |
123 | current_buffer->undo_list | |
124 | = Fcons (make_number (last_boundary_position), current_buffer->undo_list); | |
6396140a SM |
125 | } |
126 | ||
127 | /* Record an insertion that just happened or is about to happen, | |
128 | for LENGTH characters at position BEG. | |
129 | (It is possible to record an insertion before or after the fact | |
130 | because we don't need to record the contents.) */ | |
131 | ||
132 | void | |
133 | record_insert (beg, length) | |
134 | int beg, length; | |
135 | { | |
136 | Lisp_Object lbeg, lend; | |
137 | ||
138 | if (EQ (current_buffer->undo_list, Qt)) | |
139 | return; | |
140 | ||
141 | record_point (beg); | |
142 | ||
c6953be1 JB |
143 | /* If this is following another insertion and consecutive with it |
144 | in the buffer, combine the two. */ | |
38c0d37c | 145 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
146 | { |
147 | Lisp_Object elt; | |
c1d497be | 148 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 149 | if (CONSP (elt) |
c1d497be KR |
150 | && INTEGERP (XCAR (elt)) |
151 | && INTEGERP (XCDR (elt)) | |
152 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 153 | { |
f3fbd155 | 154 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
155 | return; |
156 | } | |
157 | } | |
158 | ||
53480e99 KH |
159 | XSETFASTINT (lbeg, beg); |
160 | XSETINT (lend, beg + length); | |
213861c7 JB |
161 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
162 | current_buffer->undo_list); | |
c6953be1 JB |
163 | } |
164 | ||
165 | /* Record that a deletion is about to take place, | |
e928d437 | 166 | of the characters in STRING, at location BEG. */ |
c6953be1 | 167 | |
ff1aa840 | 168 | void |
e928d437 RS |
169 | record_delete (beg, string) |
170 | int beg; | |
171 | Lisp_Object string; | |
c6953be1 | 172 | { |
e928d437 | 173 | Lisp_Object sbeg; |
c6953be1 | 174 | |
bdbe6f28 RS |
175 | if (EQ (current_buffer->undo_list, Qt)) |
176 | return; | |
177 | ||
d5db4077 | 178 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 179 | { |
6396140a SM |
180 | XSETINT (sbeg, -beg); |
181 | record_point (PT); | |
cbc1b668 KH |
182 | } |
183 | else | |
6396140a SM |
184 | { |
185 | XSETFASTINT (sbeg, beg); | |
186 | record_point (beg); | |
187 | } | |
350bce56 | 188 | |
c6953be1 | 189 | current_buffer->undo_list |
e928d437 | 190 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
191 | } |
192 | ||
714bced9 RS |
193 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
194 | This is done only when a marker points within text being deleted, | |
195 | because that's the only case where an automatic marker adjustment | |
196 | won't be inverted automatically by undoing the buffer modification. */ | |
197 | ||
ff1aa840 | 198 | void |
714bced9 RS |
199 | record_marker_adjustment (marker, adjustment) |
200 | Lisp_Object marker; | |
201 | int adjustment; | |
202 | { | |
203 | if (EQ (current_buffer->undo_list, Qt)) | |
204 | return; | |
205 | ||
206 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
207 | if (NILP (pending_boundary)) | |
208 | pending_boundary = Fcons (Qnil, Qnil); | |
209 | ||
4591d6cb | 210 | if (current_buffer != last_undo_buffer) |
714bced9 | 211 | Fundo_boundary (); |
4591d6cb | 212 | last_undo_buffer = current_buffer; |
714bced9 RS |
213 | |
214 | current_buffer->undo_list | |
215 | = Fcons (Fcons (marker, make_number (adjustment)), | |
216 | current_buffer->undo_list); | |
217 | } | |
218 | ||
c6953be1 JB |
219 | /* Record that a replacement is about to take place, |
220 | for LENGTH characters at location BEG. | |
e928d437 | 221 | The replacement must not change the number of characters. */ |
c6953be1 | 222 | |
ff1aa840 | 223 | void |
c6953be1 JB |
224 | record_change (beg, length) |
225 | int beg, length; | |
226 | { | |
e928d437 | 227 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
228 | record_insert (beg, length); |
229 | } | |
230 | \f | |
231 | /* Record that an unmodified buffer is about to be changed. | |
232 | Record the file modification date so that when undoing this entry | |
233 | we can tell whether it is obsolete because the file was saved again. */ | |
234 | ||
90dd3e4f | 235 | void |
c6953be1 JB |
236 | record_first_change () |
237 | { | |
238 | Lisp_Object high, low; | |
ad9cdce4 | 239 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
240 | |
241 | if (EQ (current_buffer->undo_list, Qt)) | |
242 | return; | |
243 | ||
4591d6cb | 244 | if (current_buffer != last_undo_buffer) |
0736cafe | 245 | Fundo_boundary (); |
4591d6cb | 246 | last_undo_buffer = current_buffer; |
0736cafe | 247 | |
ad9cdce4 RS |
248 | if (base_buffer->base_buffer) |
249 | base_buffer = base_buffer->base_buffer; | |
250 | ||
251 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
252 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
253 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
254 | } | |
255 | ||
da9319d5 RS |
256 | /* Record a change in property PROP (whose old value was VAL) |
257 | for LENGTH characters starting at position BEG in BUFFER. */ | |
258 | ||
90dd3e4f | 259 | void |
da9319d5 RS |
260 | record_property_change (beg, length, prop, value, buffer) |
261 | int beg, length; | |
262 | Lisp_Object prop, value, buffer; | |
263 | { | |
264 | Lisp_Object lbeg, lend, entry; | |
4591d6cb | 265 | struct buffer *obuf = current_buffer, *buf = XBUFFER (buffer); |
da9319d5 RS |
266 | int boundary = 0; |
267 | ||
4591d6cb | 268 | if (EQ (buf->undo_list, Qt)) |
bdbe6f28 RS |
269 | return; |
270 | ||
c58632fc RS |
271 | /* Allocate a cons cell to be the undo boundary after this command. */ |
272 | if (NILP (pending_boundary)) | |
273 | pending_boundary = Fcons (Qnil, Qnil); | |
274 | ||
4591d6cb | 275 | if (buf != last_undo_buffer) |
da9319d5 | 276 | boundary = 1; |
4591d6cb | 277 | last_undo_buffer = buf; |
da9319d5 | 278 | |
da9319d5 | 279 | /* Switch temporarily to the buffer that was changed. */ |
4591d6cb | 280 | current_buffer = buf; |
da9319d5 RS |
281 | |
282 | if (boundary) | |
283 | Fundo_boundary (); | |
284 | ||
ad9cdce4 | 285 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
286 | record_first_change (); |
287 | ||
552bdbcf KH |
288 | XSETINT (lbeg, beg); |
289 | XSETINT (lend, beg + length); | |
da9319d5 RS |
290 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
291 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
292 | ||
293 | current_buffer = obuf; | |
294 | } | |
295 | ||
c6953be1 | 296 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
297 | doc: /* Mark a boundary between units of undo. |
298 | An undo command will stop at this point, | |
299 | but another undo command will undo to the previous boundary. */) | |
300 | () | |
c6953be1 JB |
301 | { |
302 | Lisp_Object tem; | |
303 | if (EQ (current_buffer->undo_list, Qt)) | |
304 | return Qnil; | |
305 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 306 | if (!NILP (tem)) |
c58632fc RS |
307 | { |
308 | /* One way or another, cons nil onto the front of the undo list. */ | |
309 | if (!NILP (pending_boundary)) | |
310 | { | |
311 | /* If we have preallocated the cons cell to use here, | |
312 | use that one. */ | |
f3fbd155 | 313 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
314 | current_buffer->undo_list = pending_boundary; |
315 | pending_boundary = Qnil; | |
316 | } | |
317 | else | |
318 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
319 | } | |
4591d6cb SM |
320 | last_boundary_position = PT; |
321 | last_boundary_buffer = current_buffer; | |
c6953be1 JB |
322 | return Qnil; |
323 | } | |
324 | ||
325 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
326 | returning the truncated list. How this is done depends on the |
327 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
328 | In some cases this works by calling undo-outer-limit-function. */ | |
329 | ||
330 | void | |
331 | truncate_undo_list (b) | |
332 | struct buffer *b; | |
c6953be1 | 333 | { |
137e23ea | 334 | Lisp_Object list; |
c6953be1 JB |
335 | Lisp_Object prev, next, last_boundary; |
336 | int size_so_far = 0; | |
337 | ||
137e23ea RS |
338 | /* Make sure that calling undo-outer-limit-function |
339 | won't cause another GC. */ | |
340 | int count = inhibit_garbage_collection (); | |
341 | ||
342 | /* Make the buffer current to get its local values of variables such | |
343 | as undo_limit. Also so that Vundo_outer_limit_function can | |
344 | tell which buffer to operate on. */ | |
345 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
346 | set_buffer_internal (b); | |
347 | ||
348 | list = b->undo_list; | |
349 | ||
c6953be1 JB |
350 | prev = Qnil; |
351 | next = list; | |
352 | last_boundary = Qnil; | |
353 | ||
137e23ea | 354 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 355 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
356 | { |
357 | /* Add in the space occupied by this element and its chain link. */ | |
358 | size_so_far += sizeof (struct Lisp_Cons); | |
359 | ||
360 | /* Advance to next element. */ | |
361 | prev = next; | |
c1d497be | 362 | next = XCDR (next); |
c6953be1 | 363 | } |
e3d5ca1e | 364 | |
137e23ea RS |
365 | /* Always preserve at least the most recent undo record |
366 | unless it is really horribly big. | |
367 | ||
368 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
369 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
370 | ||
c1d497be | 371 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
372 | { |
373 | Lisp_Object elt; | |
c1d497be | 374 | elt = XCAR (next); |
c6953be1 JB |
375 | |
376 | /* Add in the space occupied by this element and its chain link. */ | |
377 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 378 | if (CONSP (elt)) |
c6953be1 JB |
379 | { |
380 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 381 | if (STRINGP (XCAR (elt))) |
c6953be1 | 382 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 383 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
384 | } |
385 | ||
386 | /* Advance to next element. */ | |
387 | prev = next; | |
c1d497be | 388 | next = XCDR (next); |
c6953be1 | 389 | } |
e3d5ca1e | 390 | |
137e23ea RS |
391 | /* If by the first boundary we have already passed undo_outer_limit, |
392 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
393 | if (INTEGERP (Vundo_outer_limit) |
394 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
395 | && !NILP (Vundo_outer_limit_function)) |
396 | { | |
4591d6cb SM |
397 | Lisp_Object tem; |
398 | struct buffer *temp = last_undo_buffer; | |
137e23ea RS |
399 | |
400 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
401 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
402 | if (! NILP (tem)) | |
137e23ea RS |
403 | { |
404 | /* The function is responsible for making | |
405 | any desired changes in buffer-undo-list. */ | |
406 | unbind_to (count, Qnil); | |
407 | return; | |
408 | } | |
409 | /* That function probably used the minibuffer, and if so, that | |
410 | changed last_undo_buffer. Change it back so that we don't | |
411 | force next change to make an undo boundary here. */ | |
412 | last_undo_buffer = temp; | |
413 | } | |
414 | ||
38c0d37c | 415 | if (CONSP (next)) |
c6953be1 JB |
416 | last_boundary = prev; |
417 | ||
137e23ea | 418 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 419 | while (CONSP (next)) |
c6953be1 JB |
420 | { |
421 | Lisp_Object elt; | |
c1d497be | 422 | elt = XCAR (next); |
c6953be1 JB |
423 | |
424 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 425 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 426 | tells us to truncate after it. If its size pushes past |
137e23ea | 427 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 428 | if (NILP (elt)) |
c6953be1 | 429 | { |
137e23ea | 430 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
431 | break; |
432 | last_boundary = prev; | |
137e23ea | 433 | if (size_so_far > undo_limit) |
c6953be1 JB |
434 | break; |
435 | } | |
436 | ||
437 | /* Add in the space occupied by this element and its chain link. */ | |
438 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 439 | if (CONSP (elt)) |
c6953be1 JB |
440 | { |
441 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 442 | if (STRINGP (XCAR (elt))) |
c6953be1 | 443 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 444 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
445 | } |
446 | ||
447 | /* Advance to next element. */ | |
448 | prev = next; | |
c1d497be | 449 | next = XCDR (next); |
c6953be1 JB |
450 | } |
451 | ||
452 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 453 | if (NILP (next)) |
137e23ea | 454 | ; |
c6953be1 | 455 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
456 | else if (!NILP (last_boundary)) |
457 | XSETCDR (last_boundary, Qnil); | |
458 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 459 | else |
137e23ea RS |
460 | b->undo_list = Qnil; |
461 | ||
462 | unbind_to (count, Qnil); | |
c6953be1 JB |
463 | } |
464 | \f | |
465 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
466 | doc: /* Undo N records from the front of the list LIST. |
467 | Return what remains of the list. */) | |
468 | (n, list) | |
063fb61f | 469 | Lisp_Object n, list; |
c6953be1 | 470 | { |
de65837b KH |
471 | struct gcpro gcpro1, gcpro2; |
472 | Lisp_Object next; | |
331379bf | 473 | int count = SPECPDL_INDEX (); |
de65837b | 474 | register int arg; |
4ac03187 KS |
475 | Lisp_Object oldlist; |
476 | int did_apply = 0; | |
177c0ea7 | 477 | |
c6953be1 JB |
478 | #if 0 /* This is a good feature, but would make undo-start |
479 | unable to do what is expected. */ | |
480 | Lisp_Object tem; | |
481 | ||
482 | /* If the head of the list is a boundary, it is the boundary | |
483 | preceding this command. Get rid of it and don't count it. */ | |
484 | tem = Fcar (list); | |
265a9e55 | 485 | if (NILP (tem)) |
c6953be1 JB |
486 | list = Fcdr (list); |
487 | #endif | |
488 | ||
b7826503 | 489 | CHECK_NUMBER (n); |
de65837b KH |
490 | arg = XINT (n); |
491 | next = Qnil; | |
492 | GCPRO2 (next, list); | |
4ac03187 KS |
493 | /* I don't think we need to gcpro oldlist, as we use it only |
494 | to check for EQ. ++kfs */ | |
de65837b | 495 | |
38d56be3 GM |
496 | /* In a writable buffer, enable undoing read-only text that is so |
497 | because of text properties. */ | |
498 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
499 | specbind (Qinhibit_read_only, Qt); |
500 | ||
8c757fd7 GM |
501 | /* Don't let `intangible' properties interfere with undo. */ |
502 | specbind (Qinhibit_point_motion_hooks, Qt); | |
503 | ||
4ac03187 KS |
504 | oldlist = current_buffer->undo_list; |
505 | ||
c6953be1 JB |
506 | while (arg > 0) |
507 | { | |
c3b09bbf | 508 | while (CONSP (list)) |
c6953be1 | 509 | { |
c3b09bbf SM |
510 | next = XCAR (list); |
511 | list = XCDR (list); | |
350bce56 | 512 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 513 | if (NILP (next)) |
c6953be1 | 514 | break; |
350bce56 | 515 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 516 | if (INTEGERP (next)) |
350bce56 | 517 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 518 | else if (CONSP (next)) |
c6953be1 | 519 | { |
350bce56 RS |
520 | Lisp_Object car, cdr; |
521 | ||
c3b09bbf SM |
522 | car = XCAR (next); |
523 | cdr = XCDR (next); | |
350bce56 | 524 | if (EQ (car, Qt)) |
c6953be1 | 525 | { |
350bce56 RS |
526 | /* Element (t high . low) records previous modtime. */ |
527 | Lisp_Object high, low; | |
528 | int mod_time; | |
ad9cdce4 | 529 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
530 | |
531 | high = Fcar (cdr); | |
532 | low = Fcdr (cdr); | |
d8552b2f | 533 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
534 | |
535 | if (current_buffer->base_buffer) | |
536 | base_buffer = current_buffer->base_buffer; | |
537 | ||
350bce56 RS |
538 | /* If this records an obsolete save |
539 | (not matching the actual disk file) | |
540 | then don't mark unmodified. */ | |
ad9cdce4 | 541 | if (mod_time != base_buffer->modtime) |
103dcb38 | 542 | continue; |
e6dd6080 | 543 | #ifdef CLASH_DETECTION |
350bce56 | 544 | Funlock_buffer (); |
e6dd6080 | 545 | #endif /* CLASH_DETECTION */ |
350bce56 | 546 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 547 | } |
d8552b2f | 548 | else if (EQ (car, Qnil)) |
da9319d5 | 549 | { |
6887bce5 | 550 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
551 | Lisp_Object beg, end, prop, val; |
552 | ||
553 | prop = Fcar (cdr); | |
554 | cdr = Fcdr (cdr); | |
555 | val = Fcar (cdr); | |
556 | cdr = Fcdr (cdr); | |
557 | beg = Fcar (cdr); | |
558 | end = Fcdr (cdr); | |
559 | ||
9e568684 CY |
560 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
561 | error ("Changes to be undone are outside visible portion of buffer"); | |
da9319d5 RS |
562 | Fput_text_property (beg, end, prop, val, Qnil); |
563 | } | |
38c0d37c | 564 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 565 | { |
350bce56 | 566 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
567 | |
568 | if (XINT (car) < BEGV | |
569 | || XINT (cdr) > ZV) | |
c6953be1 | 570 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
571 | /* Set point first thing, so that undoing this undo |
572 | does not send point back to where it is now. */ | |
350bce56 | 573 | Fgoto_char (car); |
f28f04cc | 574 | Fdelete_region (car, cdr); |
350bce56 | 575 | } |
49be18c9 | 576 | else if (EQ (car, Qapply)) |
6887bce5 | 577 | { |
3419757d | 578 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
579 | struct buffer *save_buffer = current_buffer; |
580 | ||
49be18c9 | 581 | car = Fcar (cdr); |
3419757d | 582 | cdr = Fcdr (cdr); |
49be18c9 KS |
583 | if (INTEGERP (car)) |
584 | { | |
3419757d SM |
585 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
586 | Lisp_Object delta = car; | |
587 | Lisp_Object start = Fcar (cdr); | |
588 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
589 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
590 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
591 | ||
592 | cdr = Fcdr (Fcdr (cdr)); | |
593 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
594 | ||
595 | /* Check that the function did what the entry said it | |
596 | would do. */ | |
597 | if (!EQ (start, Fmarker_position (start_mark)) | |
598 | || (XINT (delta) + XINT (end) | |
599 | != marker_position (end_mark))) | |
600 | error ("Changes to be undone by function different than announced"); | |
601 | Fset_marker (start_mark, Qnil, Qnil); | |
602 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 603 | } |
3419757d SM |
604 | else |
605 | apply1 (car, cdr); | |
a7a39468 KS |
606 | |
607 | if (save_buffer != current_buffer) | |
608 | error ("Undo function switched buffer"); | |
4ac03187 | 609 | did_apply = 1; |
6887bce5 | 610 | } |
38c0d37c | 611 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
612 | { |
613 | /* Element (STRING . POS) means STRING was deleted. */ | |
614 | Lisp_Object membuf; | |
615 | int pos = XINT (cdr); | |
616 | ||
617 | membuf = car; | |
618 | if (pos < 0) | |
619 | { | |
620 | if (-pos < BEGV || -pos > ZV) | |
621 | error ("Changes to be undone are outside visible portion of buffer"); | |
622 | SET_PT (-pos); | |
623 | Finsert (1, &membuf); | |
624 | } | |
625 | else | |
626 | { | |
627 | if (pos < BEGV || pos > ZV) | |
628 | error ("Changes to be undone are outside visible portion of buffer"); | |
629 | SET_PT (pos); | |
630 | ||
b2adc409 RS |
631 | /* Now that we record marker adjustments |
632 | (caused by deletion) for undo, | |
633 | we should always insert after markers, | |
634 | so that undoing the marker adjustments | |
635 | put the markers back in the right place. */ | |
636 | Finsert (1, &membuf); | |
350bce56 RS |
637 | SET_PT (pos); |
638 | } | |
c6953be1 | 639 | } |
714bced9 RS |
640 | else if (MARKERP (car) && INTEGERP (cdr)) |
641 | { | |
642 | /* (MARKER . INTEGER) means a marker MARKER | |
643 | was adjusted by INTEGER. */ | |
644 | if (XMARKER (car)->buffer) | |
645 | Fset_marker (car, | |
646 | make_number (marker_position (car) - XINT (cdr)), | |
647 | Fmarker_buffer (car)); | |
648 | } | |
c6953be1 JB |
649 | } |
650 | } | |
651 | arg--; | |
652 | } | |
653 | ||
4ac03187 KS |
654 | |
655 | /* Make sure an apply entry produces at least one undo entry, | |
656 | so the test in `undo' for continuing an undo series | |
657 | will work right. */ | |
658 | if (did_apply | |
659 | && EQ (oldlist, current_buffer->undo_list)) | |
660 | current_buffer->undo_list | |
661 | = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list); | |
662 | ||
de65837b | 663 | UNGCPRO; |
f87a68b3 | 664 | return unbind_to (count, list); |
c6953be1 | 665 | } |
6887bce5 | 666 | \f |
dfcf069d | 667 | void |
c6953be1 JB |
668 | syms_of_undo () |
669 | { | |
d67b4f80 | 670 | Qinhibit_read_only = intern_c_string ("inhibit-read-only"); |
f87a68b3 RS |
671 | staticpro (&Qinhibit_read_only); |
672 | ||
d67b4f80 | 673 | Qapply = intern_c_string ("apply"); |
49be18c9 KS |
674 | staticpro (&Qapply); |
675 | ||
c58632fc RS |
676 | pending_boundary = Qnil; |
677 | staticpro (&pending_boundary); | |
678 | ||
4591d6cb SM |
679 | last_undo_buffer = NULL; |
680 | last_boundary_buffer = NULL; | |
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. */); | |
2159bd06 | 693 | undo_limit = 80000; |
137e23ea RS |
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. */); | |
2159bd06 | 705 | undo_strong_limit = 120000; |
137e23ea | 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. */); | |
2159bd06 | 722 | Vundo_outer_limit = make_number (12000000); |
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) */ |