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, |
114f9c96 | 3 | 2005, 2006, 2007, 2008, 2009, 2010 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 | 69 | static void |
971de7fb | 70 | record_point (int pt) |
c6953be1 | 71 | { |
6396140a | 72 | int at_boundary; |
bdbe6f28 | 73 | |
4591d6cb | 74 | /* Don't record position of pt when undo_inhibit_record_point holds. */ |
8abe0f97 MR |
75 | if (undo_inhibit_record_point) |
76 | return; | |
77 | ||
c58632fc RS |
78 | /* Allocate a cons cell to be the undo boundary after this command. */ |
79 | if (NILP (pending_boundary)) | |
80 | pending_boundary = Fcons (Qnil, Qnil); | |
81 | ||
3ecc1163 MR |
82 | if ((current_buffer != last_undo_buffer) |
83 | /* Don't call Fundo_boundary for the first change. Otherwise we | |
84 | risk overwriting last_boundary_position in Fundo_boundary with | |
85 | PT of the current buffer and as a consequence not insert an | |
86 | undo boundary because last_boundary_position will equal pt in | |
87 | the test at the end of the present function (Bug#731). */ | |
88 | && (MODIFF > SAVE_MODIFF)) | |
c6953be1 | 89 | Fundo_boundary (); |
4591d6cb | 90 | last_undo_buffer = current_buffer; |
c6953be1 | 91 | |
6396140a SM |
92 | if (CONSP (current_buffer->undo_list)) |
93 | { | |
94 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
95 | marker adjustment before undo boundary. */ | |
96 | ||
97 | Lisp_Object tail = current_buffer->undo_list, elt; | |
98 | ||
99 | while (1) | |
100 | { | |
101 | if (NILP (tail)) | |
102 | elt = Qnil; | |
103 | else | |
104 | elt = XCAR (tail); | |
105 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
106 | break; | |
107 | tail = XCDR (tail); | |
108 | } | |
109 | at_boundary = NILP (elt); | |
110 | } | |
111 | else | |
112 | at_boundary = 1; | |
113 | ||
ad9cdce4 | 114 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
115 | record_first_change (); |
116 | ||
177c0ea7 | 117 | /* If we are just after an undo boundary, and |
6396140a SM |
118 | point wasn't at start of deleted range, record where it was. */ |
119 | if (at_boundary | |
4591d6cb SM |
120 | && current_buffer == last_boundary_buffer |
121 | && last_boundary_position != pt) | |
122 | current_buffer->undo_list | |
123 | = Fcons (make_number (last_boundary_position), current_buffer->undo_list); | |
6396140a SM |
124 | } |
125 | ||
126 | /* Record an insertion that just happened or is about to happen, | |
127 | for LENGTH characters at position BEG. | |
128 | (It is possible to record an insertion before or after the fact | |
129 | because we don't need to record the contents.) */ | |
130 | ||
131 | void | |
971de7fb | 132 | record_insert (int beg, int length) |
6396140a SM |
133 | { |
134 | Lisp_Object lbeg, lend; | |
135 | ||
136 | if (EQ (current_buffer->undo_list, Qt)) | |
137 | return; | |
138 | ||
139 | record_point (beg); | |
140 | ||
c6953be1 JB |
141 | /* If this is following another insertion and consecutive with it |
142 | in the buffer, combine the two. */ | |
38c0d37c | 143 | if (CONSP (current_buffer->undo_list)) |
c6953be1 JB |
144 | { |
145 | Lisp_Object elt; | |
c1d497be | 146 | elt = XCAR (current_buffer->undo_list); |
38c0d37c | 147 | if (CONSP (elt) |
c1d497be KR |
148 | && INTEGERP (XCAR (elt)) |
149 | && INTEGERP (XCDR (elt)) | |
150 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 151 | { |
f3fbd155 | 152 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
153 | return; |
154 | } | |
155 | } | |
156 | ||
53480e99 KH |
157 | XSETFASTINT (lbeg, beg); |
158 | XSETINT (lend, beg + length); | |
213861c7 JB |
159 | current_buffer->undo_list = Fcons (Fcons (lbeg, lend), |
160 | current_buffer->undo_list); | |
c6953be1 JB |
161 | } |
162 | ||
163 | /* Record that a deletion is about to take place, | |
e928d437 | 164 | of the characters in STRING, at location BEG. */ |
c6953be1 | 165 | |
ff1aa840 | 166 | void |
971de7fb | 167 | record_delete (int beg, Lisp_Object string) |
c6953be1 | 168 | { |
e928d437 | 169 | Lisp_Object sbeg; |
c6953be1 | 170 | |
bdbe6f28 RS |
171 | if (EQ (current_buffer->undo_list, Qt)) |
172 | return; | |
173 | ||
d5db4077 | 174 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 175 | { |
6396140a SM |
176 | XSETINT (sbeg, -beg); |
177 | record_point (PT); | |
cbc1b668 KH |
178 | } |
179 | else | |
6396140a SM |
180 | { |
181 | XSETFASTINT (sbeg, beg); | |
182 | record_point (beg); | |
183 | } | |
350bce56 | 184 | |
c6953be1 | 185 | current_buffer->undo_list |
e928d437 | 186 | = Fcons (Fcons (string, sbeg), current_buffer->undo_list); |
c6953be1 JB |
187 | } |
188 | ||
714bced9 RS |
189 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
190 | This is done only when a marker points within text being deleted, | |
191 | because that's the only case where an automatic marker adjustment | |
192 | won't be inverted automatically by undoing the buffer modification. */ | |
193 | ||
ff1aa840 | 194 | void |
971de7fb | 195 | record_marker_adjustment (Lisp_Object marker, int adjustment) |
714bced9 RS |
196 | { |
197 | if (EQ (current_buffer->undo_list, Qt)) | |
198 | return; | |
199 | ||
200 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
201 | if (NILP (pending_boundary)) | |
202 | pending_boundary = Fcons (Qnil, Qnil); | |
203 | ||
4591d6cb | 204 | if (current_buffer != last_undo_buffer) |
714bced9 | 205 | Fundo_boundary (); |
4591d6cb | 206 | last_undo_buffer = current_buffer; |
714bced9 RS |
207 | |
208 | current_buffer->undo_list | |
209 | = Fcons (Fcons (marker, make_number (adjustment)), | |
210 | current_buffer->undo_list); | |
211 | } | |
212 | ||
c6953be1 JB |
213 | /* Record that a replacement is about to take place, |
214 | for LENGTH characters at location BEG. | |
e928d437 | 215 | The replacement must not change the number of characters. */ |
c6953be1 | 216 | |
ff1aa840 | 217 | void |
971de7fb | 218 | record_change (int beg, int length) |
c6953be1 | 219 | { |
e928d437 | 220 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
221 | record_insert (beg, length); |
222 | } | |
223 | \f | |
224 | /* Record that an unmodified buffer is about to be changed. | |
225 | Record the file modification date so that when undoing this entry | |
226 | we can tell whether it is obsolete because the file was saved again. */ | |
227 | ||
90dd3e4f | 228 | void |
971de7fb | 229 | record_first_change (void) |
c6953be1 JB |
230 | { |
231 | Lisp_Object high, low; | |
ad9cdce4 | 232 | struct buffer *base_buffer = current_buffer; |
0736cafe RS |
233 | |
234 | if (EQ (current_buffer->undo_list, Qt)) | |
235 | return; | |
236 | ||
4591d6cb | 237 | if (current_buffer != last_undo_buffer) |
0736cafe | 238 | Fundo_boundary (); |
4591d6cb | 239 | last_undo_buffer = current_buffer; |
0736cafe | 240 | |
ad9cdce4 RS |
241 | if (base_buffer->base_buffer) |
242 | base_buffer = base_buffer->base_buffer; | |
243 | ||
244 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
245 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
c6953be1 JB |
246 | current_buffer->undo_list = Fcons (Fcons (Qt, Fcons (high, low)), current_buffer->undo_list); |
247 | } | |
248 | ||
da9319d5 RS |
249 | /* Record a change in property PROP (whose old value was VAL) |
250 | for LENGTH characters starting at position BEG in BUFFER. */ | |
251 | ||
90dd3e4f | 252 | void |
971de7fb | 253 | record_property_change (int beg, int length, Lisp_Object prop, Lisp_Object value, Lisp_Object buffer) |
da9319d5 RS |
254 | { |
255 | Lisp_Object lbeg, lend, entry; | |
4591d6cb | 256 | struct buffer *obuf = current_buffer, *buf = XBUFFER (buffer); |
da9319d5 RS |
257 | int boundary = 0; |
258 | ||
4591d6cb | 259 | if (EQ (buf->undo_list, Qt)) |
bdbe6f28 RS |
260 | return; |
261 | ||
c58632fc RS |
262 | /* Allocate a cons cell to be the undo boundary after this command. */ |
263 | if (NILP (pending_boundary)) | |
264 | pending_boundary = Fcons (Qnil, Qnil); | |
265 | ||
4591d6cb | 266 | if (buf != last_undo_buffer) |
da9319d5 | 267 | boundary = 1; |
4591d6cb | 268 | last_undo_buffer = buf; |
da9319d5 | 269 | |
da9319d5 | 270 | /* Switch temporarily to the buffer that was changed. */ |
4591d6cb | 271 | current_buffer = buf; |
da9319d5 RS |
272 | |
273 | if (boundary) | |
274 | Fundo_boundary (); | |
275 | ||
ad9cdce4 | 276 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
277 | record_first_change (); |
278 | ||
552bdbcf KH |
279 | XSETINT (lbeg, beg); |
280 | XSETINT (lend, beg + length); | |
da9319d5 RS |
281 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
282 | current_buffer->undo_list = Fcons (entry, current_buffer->undo_list); | |
283 | ||
284 | current_buffer = obuf; | |
285 | } | |
286 | ||
c6953be1 | 287 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
288 | doc: /* Mark a boundary between units of undo. |
289 | An undo command will stop at this point, | |
290 | but another undo command will undo to the previous boundary. */) | |
291 | () | |
c6953be1 JB |
292 | { |
293 | Lisp_Object tem; | |
294 | if (EQ (current_buffer->undo_list, Qt)) | |
295 | return Qnil; | |
296 | tem = Fcar (current_buffer->undo_list); | |
265a9e55 | 297 | if (!NILP (tem)) |
c58632fc RS |
298 | { |
299 | /* One way or another, cons nil onto the front of the undo list. */ | |
300 | if (!NILP (pending_boundary)) | |
301 | { | |
302 | /* If we have preallocated the cons cell to use here, | |
303 | use that one. */ | |
f3fbd155 | 304 | XSETCDR (pending_boundary, current_buffer->undo_list); |
c58632fc RS |
305 | current_buffer->undo_list = pending_boundary; |
306 | pending_boundary = Qnil; | |
307 | } | |
308 | else | |
309 | current_buffer->undo_list = Fcons (Qnil, current_buffer->undo_list); | |
310 | } | |
4591d6cb SM |
311 | last_boundary_position = PT; |
312 | last_boundary_buffer = current_buffer; | |
c6953be1 JB |
313 | return Qnil; |
314 | } | |
315 | ||
316 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
317 | returning the truncated list. How this is done depends on the |
318 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
319 | In some cases this works by calling undo-outer-limit-function. */ | |
320 | ||
321 | void | |
971de7fb | 322 | truncate_undo_list (struct buffer *b) |
c6953be1 | 323 | { |
137e23ea | 324 | Lisp_Object list; |
c6953be1 JB |
325 | Lisp_Object prev, next, last_boundary; |
326 | int size_so_far = 0; | |
327 | ||
137e23ea RS |
328 | /* Make sure that calling undo-outer-limit-function |
329 | won't cause another GC. */ | |
330 | int count = inhibit_garbage_collection (); | |
331 | ||
332 | /* Make the buffer current to get its local values of variables such | |
333 | as undo_limit. Also so that Vundo_outer_limit_function can | |
334 | tell which buffer to operate on. */ | |
335 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
336 | set_buffer_internal (b); | |
337 | ||
338 | list = b->undo_list; | |
339 | ||
c6953be1 JB |
340 | prev = Qnil; |
341 | next = list; | |
342 | last_boundary = Qnil; | |
343 | ||
137e23ea | 344 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 345 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
346 | { |
347 | /* Add in the space occupied by this element and its chain link. */ | |
348 | size_so_far += sizeof (struct Lisp_Cons); | |
349 | ||
350 | /* Advance to next element. */ | |
351 | prev = next; | |
c1d497be | 352 | next = XCDR (next); |
c6953be1 | 353 | } |
e3d5ca1e | 354 | |
137e23ea RS |
355 | /* Always preserve at least the most recent undo record |
356 | unless it is really horribly big. | |
357 | ||
358 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
359 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
360 | ||
c1d497be | 361 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
362 | { |
363 | Lisp_Object elt; | |
c1d497be | 364 | elt = XCAR (next); |
c6953be1 JB |
365 | |
366 | /* Add in the space occupied by this element and its chain link. */ | |
367 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 368 | if (CONSP (elt)) |
c6953be1 JB |
369 | { |
370 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 371 | if (STRINGP (XCAR (elt))) |
c6953be1 | 372 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 373 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
374 | } |
375 | ||
376 | /* Advance to next element. */ | |
377 | prev = next; | |
c1d497be | 378 | next = XCDR (next); |
c6953be1 | 379 | } |
e3d5ca1e | 380 | |
137e23ea RS |
381 | /* If by the first boundary we have already passed undo_outer_limit, |
382 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
383 | if (INTEGERP (Vundo_outer_limit) |
384 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
385 | && !NILP (Vundo_outer_limit_function)) |
386 | { | |
4591d6cb SM |
387 | Lisp_Object tem; |
388 | struct buffer *temp = last_undo_buffer; | |
137e23ea RS |
389 | |
390 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
391 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
392 | if (! NILP (tem)) | |
137e23ea RS |
393 | { |
394 | /* The function is responsible for making | |
395 | any desired changes in buffer-undo-list. */ | |
396 | unbind_to (count, Qnil); | |
397 | return; | |
398 | } | |
399 | /* That function probably used the minibuffer, and if so, that | |
400 | changed last_undo_buffer. Change it back so that we don't | |
401 | force next change to make an undo boundary here. */ | |
402 | last_undo_buffer = temp; | |
403 | } | |
404 | ||
38c0d37c | 405 | if (CONSP (next)) |
c6953be1 JB |
406 | last_boundary = prev; |
407 | ||
137e23ea | 408 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 409 | while (CONSP (next)) |
c6953be1 JB |
410 | { |
411 | Lisp_Object elt; | |
c1d497be | 412 | elt = XCAR (next); |
c6953be1 JB |
413 | |
414 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 415 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 416 | tells us to truncate after it. If its size pushes past |
137e23ea | 417 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 418 | if (NILP (elt)) |
c6953be1 | 419 | { |
137e23ea | 420 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
421 | break; |
422 | last_boundary = prev; | |
137e23ea | 423 | if (size_so_far > undo_limit) |
c6953be1 JB |
424 | break; |
425 | } | |
426 | ||
427 | /* Add in the space occupied by this element and its chain link. */ | |
428 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 429 | if (CONSP (elt)) |
c6953be1 JB |
430 | { |
431 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 432 | if (STRINGP (XCAR (elt))) |
c6953be1 | 433 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 434 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
435 | } |
436 | ||
437 | /* Advance to next element. */ | |
438 | prev = next; | |
c1d497be | 439 | next = XCDR (next); |
c6953be1 JB |
440 | } |
441 | ||
442 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 443 | if (NILP (next)) |
137e23ea | 444 | ; |
c6953be1 | 445 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
446 | else if (!NILP (last_boundary)) |
447 | XSETCDR (last_boundary, Qnil); | |
448 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 449 | else |
137e23ea RS |
450 | b->undo_list = Qnil; |
451 | ||
452 | unbind_to (count, Qnil); | |
c6953be1 JB |
453 | } |
454 | \f | |
455 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
456 | doc: /* Undo N records from the front of the list LIST. |
457 | Return what remains of the list. */) | |
458 | (n, list) | |
063fb61f | 459 | Lisp_Object n, list; |
c6953be1 | 460 | { |
de65837b KH |
461 | struct gcpro gcpro1, gcpro2; |
462 | Lisp_Object next; | |
331379bf | 463 | int count = SPECPDL_INDEX (); |
de65837b | 464 | register int arg; |
4ac03187 KS |
465 | Lisp_Object oldlist; |
466 | int did_apply = 0; | |
177c0ea7 | 467 | |
c6953be1 JB |
468 | #if 0 /* This is a good feature, but would make undo-start |
469 | unable to do what is expected. */ | |
470 | Lisp_Object tem; | |
471 | ||
472 | /* If the head of the list is a boundary, it is the boundary | |
473 | preceding this command. Get rid of it and don't count it. */ | |
474 | tem = Fcar (list); | |
265a9e55 | 475 | if (NILP (tem)) |
c6953be1 JB |
476 | list = Fcdr (list); |
477 | #endif | |
478 | ||
b7826503 | 479 | CHECK_NUMBER (n); |
de65837b KH |
480 | arg = XINT (n); |
481 | next = Qnil; | |
482 | GCPRO2 (next, list); | |
4ac03187 KS |
483 | /* I don't think we need to gcpro oldlist, as we use it only |
484 | to check for EQ. ++kfs */ | |
de65837b | 485 | |
38d56be3 GM |
486 | /* In a writable buffer, enable undoing read-only text that is so |
487 | because of text properties. */ | |
488 | if (NILP (current_buffer->read_only)) | |
f87a68b3 RS |
489 | specbind (Qinhibit_read_only, Qt); |
490 | ||
8c757fd7 GM |
491 | /* Don't let `intangible' properties interfere with undo. */ |
492 | specbind (Qinhibit_point_motion_hooks, Qt); | |
493 | ||
4ac03187 KS |
494 | oldlist = current_buffer->undo_list; |
495 | ||
c6953be1 JB |
496 | while (arg > 0) |
497 | { | |
c3b09bbf | 498 | while (CONSP (list)) |
c6953be1 | 499 | { |
c3b09bbf SM |
500 | next = XCAR (list); |
501 | list = XCDR (list); | |
350bce56 | 502 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 503 | if (NILP (next)) |
c6953be1 | 504 | break; |
350bce56 | 505 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 506 | if (INTEGERP (next)) |
350bce56 | 507 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 508 | else if (CONSP (next)) |
c6953be1 | 509 | { |
350bce56 RS |
510 | Lisp_Object car, cdr; |
511 | ||
c3b09bbf SM |
512 | car = XCAR (next); |
513 | cdr = XCDR (next); | |
350bce56 | 514 | if (EQ (car, Qt)) |
c6953be1 | 515 | { |
350bce56 RS |
516 | /* Element (t high . low) records previous modtime. */ |
517 | Lisp_Object high, low; | |
518 | int mod_time; | |
ad9cdce4 | 519 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
520 | |
521 | high = Fcar (cdr); | |
522 | low = Fcdr (cdr); | |
d8552b2f | 523 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
524 | |
525 | if (current_buffer->base_buffer) | |
526 | base_buffer = current_buffer->base_buffer; | |
527 | ||
350bce56 RS |
528 | /* If this records an obsolete save |
529 | (not matching the actual disk file) | |
530 | then don't mark unmodified. */ | |
ad9cdce4 | 531 | if (mod_time != base_buffer->modtime) |
103dcb38 | 532 | continue; |
e6dd6080 | 533 | #ifdef CLASH_DETECTION |
350bce56 | 534 | Funlock_buffer (); |
e6dd6080 | 535 | #endif /* CLASH_DETECTION */ |
350bce56 | 536 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 537 | } |
d8552b2f | 538 | else if (EQ (car, Qnil)) |
da9319d5 | 539 | { |
6887bce5 | 540 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
541 | Lisp_Object beg, end, prop, val; |
542 | ||
543 | prop = Fcar (cdr); | |
544 | cdr = Fcdr (cdr); | |
545 | val = Fcar (cdr); | |
546 | cdr = Fcdr (cdr); | |
547 | beg = Fcar (cdr); | |
548 | end = Fcdr (cdr); | |
549 | ||
9e568684 CY |
550 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
551 | error ("Changes to be undone are outside visible portion of buffer"); | |
da9319d5 RS |
552 | Fput_text_property (beg, end, prop, val, Qnil); |
553 | } | |
38c0d37c | 554 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 555 | { |
350bce56 | 556 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
557 | |
558 | if (XINT (car) < BEGV | |
559 | || XINT (cdr) > ZV) | |
c6953be1 | 560 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
561 | /* Set point first thing, so that undoing this undo |
562 | does not send point back to where it is now. */ | |
350bce56 | 563 | Fgoto_char (car); |
f28f04cc | 564 | Fdelete_region (car, cdr); |
350bce56 | 565 | } |
49be18c9 | 566 | else if (EQ (car, Qapply)) |
6887bce5 | 567 | { |
3419757d | 568 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
569 | struct buffer *save_buffer = current_buffer; |
570 | ||
49be18c9 | 571 | car = Fcar (cdr); |
3419757d | 572 | cdr = Fcdr (cdr); |
49be18c9 KS |
573 | if (INTEGERP (car)) |
574 | { | |
3419757d SM |
575 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
576 | Lisp_Object delta = car; | |
577 | Lisp_Object start = Fcar (cdr); | |
578 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
579 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
580 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
581 | ||
582 | cdr = Fcdr (Fcdr (cdr)); | |
583 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
584 | ||
585 | /* Check that the function did what the entry said it | |
586 | would do. */ | |
587 | if (!EQ (start, Fmarker_position (start_mark)) | |
588 | || (XINT (delta) + XINT (end) | |
589 | != marker_position (end_mark))) | |
590 | error ("Changes to be undone by function different than announced"); | |
591 | Fset_marker (start_mark, Qnil, Qnil); | |
592 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 593 | } |
3419757d SM |
594 | else |
595 | apply1 (car, cdr); | |
a7a39468 KS |
596 | |
597 | if (save_buffer != current_buffer) | |
598 | error ("Undo function switched buffer"); | |
4ac03187 | 599 | did_apply = 1; |
6887bce5 | 600 | } |
38c0d37c | 601 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
602 | { |
603 | /* Element (STRING . POS) means STRING was deleted. */ | |
604 | Lisp_Object membuf; | |
605 | int pos = XINT (cdr); | |
606 | ||
607 | membuf = car; | |
608 | if (pos < 0) | |
609 | { | |
610 | if (-pos < BEGV || -pos > ZV) | |
611 | error ("Changes to be undone are outside visible portion of buffer"); | |
612 | SET_PT (-pos); | |
613 | Finsert (1, &membuf); | |
614 | } | |
615 | else | |
616 | { | |
617 | if (pos < BEGV || pos > ZV) | |
618 | error ("Changes to be undone are outside visible portion of buffer"); | |
619 | SET_PT (pos); | |
620 | ||
b2adc409 RS |
621 | /* Now that we record marker adjustments |
622 | (caused by deletion) for undo, | |
623 | we should always insert after markers, | |
624 | so that undoing the marker adjustments | |
625 | put the markers back in the right place. */ | |
626 | Finsert (1, &membuf); | |
350bce56 RS |
627 | SET_PT (pos); |
628 | } | |
c6953be1 | 629 | } |
714bced9 RS |
630 | else if (MARKERP (car) && INTEGERP (cdr)) |
631 | { | |
632 | /* (MARKER . INTEGER) means a marker MARKER | |
633 | was adjusted by INTEGER. */ | |
634 | if (XMARKER (car)->buffer) | |
635 | Fset_marker (car, | |
636 | make_number (marker_position (car) - XINT (cdr)), | |
637 | Fmarker_buffer (car)); | |
638 | } | |
c6953be1 JB |
639 | } |
640 | } | |
641 | arg--; | |
642 | } | |
643 | ||
4ac03187 KS |
644 | |
645 | /* Make sure an apply entry produces at least one undo entry, | |
646 | so the test in `undo' for continuing an undo series | |
647 | will work right. */ | |
648 | if (did_apply | |
649 | && EQ (oldlist, current_buffer->undo_list)) | |
650 | current_buffer->undo_list | |
651 | = Fcons (list3 (Qapply, Qcdr, Qnil), current_buffer->undo_list); | |
652 | ||
de65837b | 653 | UNGCPRO; |
f87a68b3 | 654 | return unbind_to (count, list); |
c6953be1 | 655 | } |
6887bce5 | 656 | \f |
dfcf069d | 657 | void |
971de7fb | 658 | syms_of_undo (void) |
c6953be1 | 659 | { |
d67b4f80 | 660 | Qinhibit_read_only = intern_c_string ("inhibit-read-only"); |
f87a68b3 RS |
661 | staticpro (&Qinhibit_read_only); |
662 | ||
d67b4f80 | 663 | Qapply = intern_c_string ("apply"); |
49be18c9 KS |
664 | staticpro (&Qapply); |
665 | ||
c58632fc RS |
666 | pending_boundary = Qnil; |
667 | staticpro (&pending_boundary); | |
668 | ||
4591d6cb SM |
669 | last_undo_buffer = NULL; |
670 | last_boundary_buffer = NULL; | |
671 | ||
c6953be1 JB |
672 | defsubr (&Sprimitive_undo); |
673 | defsubr (&Sundo_boundary); | |
137e23ea RS |
674 | |
675 | DEFVAR_INT ("undo-limit", &undo_limit, | |
676 | doc: /* Keep no more undo information once it exceeds this size. | |
677 | This limit is applied when garbage collection happens. | |
678 | When a previous command increases the total undo list size past this | |
679 | value, the earlier commands that came before it are forgotten. | |
680 | ||
681 | The size is counted as the number of bytes occupied, | |
682 | which includes both saved text and other data. */); | |
2159bd06 | 683 | undo_limit = 80000; |
137e23ea RS |
684 | |
685 | DEFVAR_INT ("undo-strong-limit", &undo_strong_limit, | |
686 | doc: /* Don't keep more than this much size of undo information. | |
687 | This limit is applied when garbage collection happens. | |
688 | When a previous command increases the total undo list size past this | |
689 | value, that command and the earlier commands that came before it are forgotten. | |
690 | However, the most recent buffer-modifying command's undo info | |
691 | is never discarded for this reason. | |
692 | ||
693 | The size is counted as the number of bytes occupied, | |
694 | which includes both saved text and other data. */); | |
2159bd06 | 695 | undo_strong_limit = 120000; |
137e23ea | 696 | |
81c1cf71 | 697 | DEFVAR_LISP ("undo-outer-limit", &Vundo_outer_limit, |
137e23ea RS |
698 | doc: /* Outer limit on size of undo information for one command. |
699 | At garbage collection time, if the current command has produced | |
62d776fd LT |
700 | more than this much undo information, it discards the info and displays |
701 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 702 | |
62d776fd LT |
703 | The size is counted as the number of bytes occupied, which includes |
704 | both saved text and other data. A value of nil means no limit. In | |
705 | this case, accumulating one huge undo entry could make Emacs crash as | |
706 | a result of memory overflow. | |
137e23ea RS |
707 | |
708 | In fact, this calls the function which is the value of | |
709 | `undo-outer-limit-function' with one argument, the size. | |
710 | The text above describes the behavior of the function | |
711 | that variable usually specifies. */); | |
2159bd06 | 712 | Vundo_outer_limit = make_number (12000000); |
137e23ea RS |
713 | |
714 | DEFVAR_LISP ("undo-outer-limit-function", &Vundo_outer_limit_function, | |
715 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. | |
716 | This function is called with one argument, the current undo list size | |
717 | for the most recent command (since the last undo boundary). | |
718 | If the function returns t, that means truncation has been fully handled. | |
719 | If it returns nil, the other forms of truncation are done. | |
720 | ||
721 | Garbage collection is inhibited around the call to this function, | |
722 | so it must make sure not to do a lot of consing. */); | |
723 | Vundo_outer_limit_function = Qnil; | |
8abe0f97 MR |
724 | |
725 | DEFVAR_BOOL ("undo-inhibit-record-point", &undo_inhibit_record_point, | |
726 | doc: /* Non-nil means do not record `point' in `buffer-undo-list'. */); | |
727 | undo_inhibit_record_point = 0; | |
c6953be1 | 728 | } |
ab5796a9 MB |
729 | |
730 | /* arch-tag: d546ee01-4aed-4ffb-bb8b-eefaae50d38a | |
731 | (do not change this comment) */ |