Commit | Line | Data |
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c6953be1 | 1 | /* undo handling for GNU Emacs. |
73b0cd50 | 2 | Copyright (C) 1990, 1993-1994, 2000-2011 Free Software Foundation, Inc. |
c6953be1 JB |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
3b7ad313 | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
3b7ad313 | 10 | |
c6953be1 | 11 | GNU Emacs is distributed in the hope that it will be useful, |
3b7ad313 EN |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
c6953be1 JB |
18 | |
19 | ||
18160b98 | 20 | #include <config.h> |
d7306fe6 | 21 | #include <setjmp.h> |
c6953be1 JB |
22 | #include "lisp.h" |
23 | #include "buffer.h" | |
4e665715 | 24 | #include "commands.h" |
91e25f5e | 25 | #include "window.h" |
c6953be1 JB |
26 | |
27 | /* Last buffer for which undo information was recorded. */ | |
4591d6cb | 28 | /* BEWARE: This is not traced by the GC, so never dereference it! */ |
2b96acb7 | 29 | static struct buffer *last_undo_buffer; |
4591d6cb SM |
30 | |
31 | /* Position of point last time we inserted a boundary. */ | |
2b96acb7 PE |
32 | static struct buffer *last_boundary_buffer; |
33 | static EMACS_INT last_boundary_position; | |
c6953be1 | 34 | |
f87a68b3 RS |
35 | Lisp_Object Qinhibit_read_only; |
36 | ||
49be18c9 KS |
37 | /* Marker for function call undo list elements. */ |
38 | ||
39 | Lisp_Object Qapply; | |
40 | ||
c58632fc RS |
41 | /* The first time a command records something for undo. |
42 | it also allocates the undo-boundary object | |
43 | which will be added to the list at the end of the command. | |
44 | This ensures we can't run out of space while trying to make | |
45 | an undo-boundary. */ | |
2b96acb7 | 46 | static Lisp_Object pending_boundary; |
c58632fc | 47 | |
6396140a | 48 | /* Record point as it was at beginning of this command (if necessary) |
8abe0f97 | 49 | and prepare the undo info for recording a change. |
6396140a SM |
50 | PT is the position of point that will naturally occur as a result of the |
51 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 52 | |
6396140a | 53 | static void |
c8a66ab8 | 54 | record_point (EMACS_INT pt) |
c6953be1 | 55 | { |
6396140a | 56 | int at_boundary; |
bdbe6f28 | 57 | |
4591d6cb | 58 | /* Don't record position of pt when undo_inhibit_record_point holds. */ |
8abe0f97 MR |
59 | if (undo_inhibit_record_point) |
60 | return; | |
61 | ||
c58632fc RS |
62 | /* Allocate a cons cell to be the undo boundary after this command. */ |
63 | if (NILP (pending_boundary)) | |
64 | pending_boundary = Fcons (Qnil, Qnil); | |
65 | ||
3ecc1163 MR |
66 | if ((current_buffer != last_undo_buffer) |
67 | /* Don't call Fundo_boundary for the first change. Otherwise we | |
68 | risk overwriting last_boundary_position in Fundo_boundary with | |
69 | PT of the current buffer and as a consequence not insert an | |
70 | undo boundary because last_boundary_position will equal pt in | |
71 | the test at the end of the present function (Bug#731). */ | |
72 | && (MODIFF > SAVE_MODIFF)) | |
c6953be1 | 73 | Fundo_boundary (); |
4591d6cb | 74 | last_undo_buffer = current_buffer; |
c6953be1 | 75 | |
4b4deea2 | 76 | if (CONSP (BVAR (current_buffer, undo_list))) |
6396140a SM |
77 | { |
78 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
79 | marker adjustment before undo boundary. */ | |
80 | ||
4b4deea2 | 81 | Lisp_Object tail = BVAR (current_buffer, undo_list), elt; |
6396140a SM |
82 | |
83 | while (1) | |
84 | { | |
85 | if (NILP (tail)) | |
86 | elt = Qnil; | |
87 | else | |
88 | elt = XCAR (tail); | |
89 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
90 | break; | |
91 | tail = XCDR (tail); | |
92 | } | |
93 | at_boundary = NILP (elt); | |
94 | } | |
95 | else | |
96 | at_boundary = 1; | |
97 | ||
ad9cdce4 | 98 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
99 | record_first_change (); |
100 | ||
177c0ea7 | 101 | /* If we are just after an undo boundary, and |
6396140a SM |
102 | point wasn't at start of deleted range, record where it was. */ |
103 | if (at_boundary | |
4591d6cb SM |
104 | && current_buffer == last_boundary_buffer |
105 | && last_boundary_position != pt) | |
4b4deea2 TT |
106 | BVAR (current_buffer, undo_list) |
107 | = Fcons (make_number (last_boundary_position), BVAR (current_buffer, undo_list)); | |
6396140a SM |
108 | } |
109 | ||
110 | /* Record an insertion that just happened or is about to happen, | |
111 | for LENGTH characters at position BEG. | |
112 | (It is possible to record an insertion before or after the fact | |
113 | because we don't need to record the contents.) */ | |
114 | ||
115 | void | |
c8a66ab8 | 116 | record_insert (EMACS_INT beg, EMACS_INT length) |
6396140a SM |
117 | { |
118 | Lisp_Object lbeg, lend; | |
119 | ||
4b4deea2 | 120 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
6396140a SM |
121 | return; |
122 | ||
123 | record_point (beg); | |
124 | ||
c6953be1 JB |
125 | /* If this is following another insertion and consecutive with it |
126 | in the buffer, combine the two. */ | |
4b4deea2 | 127 | if (CONSP (BVAR (current_buffer, undo_list))) |
c6953be1 JB |
128 | { |
129 | Lisp_Object elt; | |
4b4deea2 | 130 | elt = XCAR (BVAR (current_buffer, undo_list)); |
38c0d37c | 131 | if (CONSP (elt) |
c1d497be KR |
132 | && INTEGERP (XCAR (elt)) |
133 | && INTEGERP (XCDR (elt)) | |
134 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 135 | { |
f3fbd155 | 136 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
137 | return; |
138 | } | |
139 | } | |
140 | ||
53480e99 KH |
141 | XSETFASTINT (lbeg, beg); |
142 | XSETINT (lend, beg + length); | |
4b4deea2 TT |
143 | BVAR (current_buffer, undo_list) = Fcons (Fcons (lbeg, lend), |
144 | BVAR (current_buffer, undo_list)); | |
c6953be1 JB |
145 | } |
146 | ||
147 | /* Record that a deletion is about to take place, | |
e928d437 | 148 | of the characters in STRING, at location BEG. */ |
c6953be1 | 149 | |
ff1aa840 | 150 | void |
c8a66ab8 | 151 | record_delete (EMACS_INT beg, Lisp_Object string) |
c6953be1 | 152 | { |
e928d437 | 153 | Lisp_Object sbeg; |
c6953be1 | 154 | |
4b4deea2 | 155 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
bdbe6f28 RS |
156 | return; |
157 | ||
d5db4077 | 158 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 159 | { |
6396140a SM |
160 | XSETINT (sbeg, -beg); |
161 | record_point (PT); | |
cbc1b668 KH |
162 | } |
163 | else | |
6396140a SM |
164 | { |
165 | XSETFASTINT (sbeg, beg); | |
166 | record_point (beg); | |
167 | } | |
350bce56 | 168 | |
4b4deea2 TT |
169 | BVAR (current_buffer, undo_list) |
170 | = Fcons (Fcons (string, sbeg), BVAR (current_buffer, undo_list)); | |
c6953be1 JB |
171 | } |
172 | ||
714bced9 RS |
173 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
174 | This is done only when a marker points within text being deleted, | |
175 | because that's the only case where an automatic marker adjustment | |
176 | won't be inverted automatically by undoing the buffer modification. */ | |
177 | ||
ff1aa840 | 178 | void |
c8a66ab8 | 179 | record_marker_adjustment (Lisp_Object marker, EMACS_INT adjustment) |
714bced9 | 180 | { |
4b4deea2 | 181 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
714bced9 RS |
182 | return; |
183 | ||
184 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
185 | if (NILP (pending_boundary)) | |
186 | pending_boundary = Fcons (Qnil, Qnil); | |
187 | ||
4591d6cb | 188 | if (current_buffer != last_undo_buffer) |
714bced9 | 189 | Fundo_boundary (); |
4591d6cb | 190 | last_undo_buffer = current_buffer; |
714bced9 | 191 | |
4b4deea2 | 192 | BVAR (current_buffer, undo_list) |
714bced9 | 193 | = Fcons (Fcons (marker, make_number (adjustment)), |
4b4deea2 | 194 | BVAR (current_buffer, undo_list)); |
714bced9 RS |
195 | } |
196 | ||
c6953be1 JB |
197 | /* Record that a replacement is about to take place, |
198 | for LENGTH characters at location BEG. | |
e928d437 | 199 | The replacement must not change the number of characters. */ |
c6953be1 | 200 | |
ff1aa840 | 201 | void |
c8a66ab8 | 202 | record_change (EMACS_INT beg, EMACS_INT length) |
c6953be1 | 203 | { |
e928d437 | 204 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
205 | record_insert (beg, length); |
206 | } | |
207 | \f | |
208 | /* Record that an unmodified buffer is about to be changed. | |
209 | Record the file modification date so that when undoing this entry | |
210 | we can tell whether it is obsolete because the file was saved again. */ | |
211 | ||
90dd3e4f | 212 | void |
971de7fb | 213 | record_first_change (void) |
c6953be1 JB |
214 | { |
215 | Lisp_Object high, low; | |
ad9cdce4 | 216 | struct buffer *base_buffer = current_buffer; |
0736cafe | 217 | |
4b4deea2 | 218 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
0736cafe RS |
219 | return; |
220 | ||
4591d6cb | 221 | if (current_buffer != last_undo_buffer) |
0736cafe | 222 | Fundo_boundary (); |
4591d6cb | 223 | last_undo_buffer = current_buffer; |
0736cafe | 224 | |
ad9cdce4 RS |
225 | if (base_buffer->base_buffer) |
226 | base_buffer = base_buffer->base_buffer; | |
227 | ||
228 | XSETFASTINT (high, (base_buffer->modtime >> 16) & 0xffff); | |
229 | XSETFASTINT (low, base_buffer->modtime & 0xffff); | |
4b4deea2 | 230 | BVAR (current_buffer, undo_list) = Fcons (Fcons (Qt, Fcons (high, low)), BVAR (current_buffer, undo_list)); |
c6953be1 JB |
231 | } |
232 | ||
da9319d5 RS |
233 | /* Record a change in property PROP (whose old value was VAL) |
234 | for LENGTH characters starting at position BEG in BUFFER. */ | |
235 | ||
90dd3e4f | 236 | void |
c8a66ab8 EZ |
237 | record_property_change (EMACS_INT beg, EMACS_INT length, |
238 | Lisp_Object prop, Lisp_Object value, | |
239 | Lisp_Object buffer) | |
da9319d5 RS |
240 | { |
241 | Lisp_Object lbeg, lend, entry; | |
4591d6cb | 242 | struct buffer *obuf = current_buffer, *buf = XBUFFER (buffer); |
da9319d5 RS |
243 | int boundary = 0; |
244 | ||
4b4deea2 | 245 | if (EQ (BVAR (buf, undo_list), Qt)) |
bdbe6f28 RS |
246 | return; |
247 | ||
c58632fc RS |
248 | /* Allocate a cons cell to be the undo boundary after this command. */ |
249 | if (NILP (pending_boundary)) | |
250 | pending_boundary = Fcons (Qnil, Qnil); | |
251 | ||
4591d6cb | 252 | if (buf != last_undo_buffer) |
da9319d5 | 253 | boundary = 1; |
4591d6cb | 254 | last_undo_buffer = buf; |
da9319d5 | 255 | |
da9319d5 | 256 | /* Switch temporarily to the buffer that was changed. */ |
4591d6cb | 257 | current_buffer = buf; |
da9319d5 RS |
258 | |
259 | if (boundary) | |
260 | Fundo_boundary (); | |
261 | ||
ad9cdce4 | 262 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
263 | record_first_change (); |
264 | ||
552bdbcf KH |
265 | XSETINT (lbeg, beg); |
266 | XSETINT (lend, beg + length); | |
da9319d5 | 267 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
4b4deea2 | 268 | BVAR (current_buffer, undo_list) = Fcons (entry, BVAR (current_buffer, undo_list)); |
da9319d5 RS |
269 | |
270 | current_buffer = obuf; | |
271 | } | |
272 | ||
a7ca3326 | 273 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
274 | doc: /* Mark a boundary between units of undo. |
275 | An undo command will stop at this point, | |
276 | but another undo command will undo to the previous boundary. */) | |
5842a27b | 277 | (void) |
c6953be1 JB |
278 | { |
279 | Lisp_Object tem; | |
4b4deea2 | 280 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
c6953be1 | 281 | return Qnil; |
4b4deea2 | 282 | tem = Fcar (BVAR (current_buffer, undo_list)); |
265a9e55 | 283 | if (!NILP (tem)) |
c58632fc RS |
284 | { |
285 | /* One way or another, cons nil onto the front of the undo list. */ | |
286 | if (!NILP (pending_boundary)) | |
287 | { | |
288 | /* If we have preallocated the cons cell to use here, | |
289 | use that one. */ | |
4b4deea2 TT |
290 | XSETCDR (pending_boundary, BVAR (current_buffer, undo_list)); |
291 | BVAR (current_buffer, undo_list) = pending_boundary; | |
c58632fc RS |
292 | pending_boundary = Qnil; |
293 | } | |
294 | else | |
4b4deea2 | 295 | BVAR (current_buffer, undo_list) = Fcons (Qnil, BVAR (current_buffer, undo_list)); |
c58632fc | 296 | } |
4591d6cb SM |
297 | last_boundary_position = PT; |
298 | last_boundary_buffer = current_buffer; | |
c6953be1 JB |
299 | return Qnil; |
300 | } | |
301 | ||
302 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
303 | returning the truncated list. How this is done depends on the |
304 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
305 | In some cases this works by calling undo-outer-limit-function. */ | |
306 | ||
307 | void | |
971de7fb | 308 | truncate_undo_list (struct buffer *b) |
c6953be1 | 309 | { |
137e23ea | 310 | Lisp_Object list; |
c6953be1 JB |
311 | Lisp_Object prev, next, last_boundary; |
312 | int size_so_far = 0; | |
313 | ||
137e23ea RS |
314 | /* Make sure that calling undo-outer-limit-function |
315 | won't cause another GC. */ | |
316 | int count = inhibit_garbage_collection (); | |
317 | ||
318 | /* Make the buffer current to get its local values of variables such | |
319 | as undo_limit. Also so that Vundo_outer_limit_function can | |
320 | tell which buffer to operate on. */ | |
321 | record_unwind_protect (set_buffer_if_live, Fcurrent_buffer ()); | |
322 | set_buffer_internal (b); | |
323 | ||
4b4deea2 | 324 | list = BVAR (b, undo_list); |
137e23ea | 325 | |
c6953be1 JB |
326 | prev = Qnil; |
327 | next = list; | |
328 | last_boundary = Qnil; | |
329 | ||
137e23ea | 330 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 331 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
332 | { |
333 | /* Add in the space occupied by this element and its chain link. */ | |
334 | size_so_far += sizeof (struct Lisp_Cons); | |
335 | ||
336 | /* Advance to next element. */ | |
337 | prev = next; | |
c1d497be | 338 | next = XCDR (next); |
c6953be1 | 339 | } |
e3d5ca1e | 340 | |
137e23ea RS |
341 | /* Always preserve at least the most recent undo record |
342 | unless it is really horribly big. | |
343 | ||
344 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
345 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
346 | ||
c1d497be | 347 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
348 | { |
349 | Lisp_Object elt; | |
c1d497be | 350 | elt = 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); | |
38c0d37c | 354 | if (CONSP (elt)) |
c6953be1 JB |
355 | { |
356 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 357 | if (STRINGP (XCAR (elt))) |
c6953be1 | 358 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 359 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
360 | } |
361 | ||
362 | /* Advance to next element. */ | |
363 | prev = next; | |
c1d497be | 364 | next = XCDR (next); |
c6953be1 | 365 | } |
e3d5ca1e | 366 | |
137e23ea RS |
367 | /* If by the first boundary we have already passed undo_outer_limit, |
368 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
369 | if (INTEGERP (Vundo_outer_limit) |
370 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
371 | && !NILP (Vundo_outer_limit_function)) |
372 | { | |
4591d6cb SM |
373 | Lisp_Object tem; |
374 | struct buffer *temp = last_undo_buffer; | |
137e23ea RS |
375 | |
376 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
377 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
378 | if (! NILP (tem)) | |
137e23ea RS |
379 | { |
380 | /* The function is responsible for making | |
381 | any desired changes in buffer-undo-list. */ | |
382 | unbind_to (count, Qnil); | |
383 | return; | |
384 | } | |
385 | /* That function probably used the minibuffer, and if so, that | |
386 | changed last_undo_buffer. Change it back so that we don't | |
387 | force next change to make an undo boundary here. */ | |
388 | last_undo_buffer = temp; | |
389 | } | |
390 | ||
38c0d37c | 391 | if (CONSP (next)) |
c6953be1 JB |
392 | last_boundary = prev; |
393 | ||
137e23ea | 394 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 395 | while (CONSP (next)) |
c6953be1 JB |
396 | { |
397 | Lisp_Object elt; | |
c1d497be | 398 | elt = XCAR (next); |
c6953be1 JB |
399 | |
400 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 401 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 402 | tells us to truncate after it. If its size pushes past |
137e23ea | 403 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 404 | if (NILP (elt)) |
c6953be1 | 405 | { |
137e23ea | 406 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
407 | break; |
408 | last_boundary = prev; | |
137e23ea | 409 | if (size_so_far > undo_limit) |
c6953be1 JB |
410 | break; |
411 | } | |
412 | ||
413 | /* Add in the space occupied by this element and its chain link. */ | |
414 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 415 | if (CONSP (elt)) |
c6953be1 JB |
416 | { |
417 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 418 | if (STRINGP (XCAR (elt))) |
c6953be1 | 419 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 420 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
421 | } |
422 | ||
423 | /* Advance to next element. */ | |
424 | prev = next; | |
c1d497be | 425 | next = XCDR (next); |
c6953be1 JB |
426 | } |
427 | ||
428 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 429 | if (NILP (next)) |
137e23ea | 430 | ; |
c6953be1 | 431 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
432 | else if (!NILP (last_boundary)) |
433 | XSETCDR (last_boundary, Qnil); | |
434 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 435 | else |
4b4deea2 | 436 | BVAR (b, undo_list) = Qnil; |
137e23ea RS |
437 | |
438 | unbind_to (count, Qnil); | |
c6953be1 JB |
439 | } |
440 | \f | |
441 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
442 | doc: /* Undo N records from the front of the list LIST. |
443 | Return what remains of the list. */) | |
5842a27b | 444 | (Lisp_Object n, Lisp_Object list) |
c6953be1 | 445 | { |
de65837b KH |
446 | struct gcpro gcpro1, gcpro2; |
447 | Lisp_Object next; | |
331379bf | 448 | int count = SPECPDL_INDEX (); |
de65837b | 449 | register int arg; |
4ac03187 KS |
450 | Lisp_Object oldlist; |
451 | int did_apply = 0; | |
177c0ea7 | 452 | |
c6953be1 JB |
453 | #if 0 /* This is a good feature, but would make undo-start |
454 | unable to do what is expected. */ | |
455 | Lisp_Object tem; | |
456 | ||
457 | /* If the head of the list is a boundary, it is the boundary | |
458 | preceding this command. Get rid of it and don't count it. */ | |
459 | tem = Fcar (list); | |
265a9e55 | 460 | if (NILP (tem)) |
c6953be1 JB |
461 | list = Fcdr (list); |
462 | #endif | |
463 | ||
b7826503 | 464 | CHECK_NUMBER (n); |
de65837b KH |
465 | arg = XINT (n); |
466 | next = Qnil; | |
467 | GCPRO2 (next, list); | |
4ac03187 KS |
468 | /* I don't think we need to gcpro oldlist, as we use it only |
469 | to check for EQ. ++kfs */ | |
de65837b | 470 | |
38d56be3 GM |
471 | /* In a writable buffer, enable undoing read-only text that is so |
472 | because of text properties. */ | |
4b4deea2 | 473 | if (NILP (BVAR (current_buffer, read_only))) |
f87a68b3 RS |
474 | specbind (Qinhibit_read_only, Qt); |
475 | ||
8c757fd7 GM |
476 | /* Don't let `intangible' properties interfere with undo. */ |
477 | specbind (Qinhibit_point_motion_hooks, Qt); | |
478 | ||
4b4deea2 | 479 | oldlist = BVAR (current_buffer, undo_list); |
4ac03187 | 480 | |
c6953be1 JB |
481 | while (arg > 0) |
482 | { | |
c3b09bbf | 483 | while (CONSP (list)) |
c6953be1 | 484 | { |
c3b09bbf SM |
485 | next = XCAR (list); |
486 | list = XCDR (list); | |
350bce56 | 487 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 488 | if (NILP (next)) |
c6953be1 | 489 | break; |
350bce56 | 490 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 491 | if (INTEGERP (next)) |
350bce56 | 492 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 493 | else if (CONSP (next)) |
c6953be1 | 494 | { |
350bce56 RS |
495 | Lisp_Object car, cdr; |
496 | ||
c3b09bbf SM |
497 | car = XCAR (next); |
498 | cdr = XCDR (next); | |
350bce56 | 499 | if (EQ (car, Qt)) |
c6953be1 | 500 | { |
350bce56 RS |
501 | /* Element (t high . low) records previous modtime. */ |
502 | Lisp_Object high, low; | |
503 | int mod_time; | |
ad9cdce4 | 504 | struct buffer *base_buffer = current_buffer; |
350bce56 RS |
505 | |
506 | high = Fcar (cdr); | |
507 | low = Fcdr (cdr); | |
d8552b2f | 508 | mod_time = (XFASTINT (high) << 16) + XFASTINT (low); |
ad9cdce4 RS |
509 | |
510 | if (current_buffer->base_buffer) | |
511 | base_buffer = current_buffer->base_buffer; | |
512 | ||
350bce56 RS |
513 | /* If this records an obsolete save |
514 | (not matching the actual disk file) | |
515 | then don't mark unmodified. */ | |
ad9cdce4 | 516 | if (mod_time != base_buffer->modtime) |
103dcb38 | 517 | continue; |
e6dd6080 | 518 | #ifdef CLASH_DETECTION |
350bce56 | 519 | Funlock_buffer (); |
e6dd6080 | 520 | #endif /* CLASH_DETECTION */ |
350bce56 | 521 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 522 | } |
d8552b2f | 523 | else if (EQ (car, Qnil)) |
da9319d5 | 524 | { |
6887bce5 | 525 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
526 | Lisp_Object beg, end, prop, val; |
527 | ||
528 | prop = Fcar (cdr); | |
529 | cdr = Fcdr (cdr); | |
530 | val = Fcar (cdr); | |
531 | cdr = Fcdr (cdr); | |
532 | beg = Fcar (cdr); | |
533 | end = Fcdr (cdr); | |
534 | ||
9e568684 CY |
535 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
536 | error ("Changes to be undone are outside visible portion of buffer"); | |
da9319d5 RS |
537 | Fput_text_property (beg, end, prop, val, Qnil); |
538 | } | |
38c0d37c | 539 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 540 | { |
350bce56 | 541 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
542 | |
543 | if (XINT (car) < BEGV | |
544 | || XINT (cdr) > ZV) | |
c6953be1 | 545 | error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
546 | /* Set point first thing, so that undoing this undo |
547 | does not send point back to where it is now. */ | |
350bce56 | 548 | Fgoto_char (car); |
f28f04cc | 549 | Fdelete_region (car, cdr); |
350bce56 | 550 | } |
49be18c9 | 551 | else if (EQ (car, Qapply)) |
6887bce5 | 552 | { |
3419757d | 553 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
554 | struct buffer *save_buffer = current_buffer; |
555 | ||
49be18c9 | 556 | car = Fcar (cdr); |
3419757d | 557 | cdr = Fcdr (cdr); |
49be18c9 KS |
558 | if (INTEGERP (car)) |
559 | { | |
3419757d SM |
560 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
561 | Lisp_Object delta = car; | |
562 | Lisp_Object start = Fcar (cdr); | |
563 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
564 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
565 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
566 | ||
567 | cdr = Fcdr (Fcdr (cdr)); | |
568 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
569 | ||
570 | /* Check that the function did what the entry said it | |
571 | would do. */ | |
572 | if (!EQ (start, Fmarker_position (start_mark)) | |
573 | || (XINT (delta) + XINT (end) | |
574 | != marker_position (end_mark))) | |
575 | error ("Changes to be undone by function different than announced"); | |
576 | Fset_marker (start_mark, Qnil, Qnil); | |
577 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 578 | } |
3419757d SM |
579 | else |
580 | apply1 (car, cdr); | |
a7a39468 KS |
581 | |
582 | if (save_buffer != current_buffer) | |
583 | error ("Undo function switched buffer"); | |
4ac03187 | 584 | did_apply = 1; |
6887bce5 | 585 | } |
38c0d37c | 586 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
587 | { |
588 | /* Element (STRING . POS) means STRING was deleted. */ | |
589 | Lisp_Object membuf; | |
c8a66ab8 | 590 | EMACS_INT pos = XINT (cdr); |
350bce56 RS |
591 | |
592 | membuf = car; | |
593 | if (pos < 0) | |
594 | { | |
595 | if (-pos < BEGV || -pos > ZV) | |
596 | error ("Changes to be undone are outside visible portion of buffer"); | |
597 | SET_PT (-pos); | |
598 | Finsert (1, &membuf); | |
599 | } | |
600 | else | |
601 | { | |
602 | if (pos < BEGV || pos > ZV) | |
603 | error ("Changes to be undone are outside visible portion of buffer"); | |
604 | SET_PT (pos); | |
605 | ||
b2adc409 RS |
606 | /* Now that we record marker adjustments |
607 | (caused by deletion) for undo, | |
608 | we should always insert after markers, | |
609 | so that undoing the marker adjustments | |
610 | put the markers back in the right place. */ | |
611 | Finsert (1, &membuf); | |
350bce56 RS |
612 | SET_PT (pos); |
613 | } | |
c6953be1 | 614 | } |
714bced9 RS |
615 | else if (MARKERP (car) && INTEGERP (cdr)) |
616 | { | |
617 | /* (MARKER . INTEGER) means a marker MARKER | |
618 | was adjusted by INTEGER. */ | |
619 | if (XMARKER (car)->buffer) | |
620 | Fset_marker (car, | |
621 | make_number (marker_position (car) - XINT (cdr)), | |
622 | Fmarker_buffer (car)); | |
623 | } | |
c6953be1 JB |
624 | } |
625 | } | |
626 | arg--; | |
627 | } | |
628 | ||
4ac03187 KS |
629 | |
630 | /* Make sure an apply entry produces at least one undo entry, | |
631 | so the test in `undo' for continuing an undo series | |
632 | will work right. */ | |
633 | if (did_apply | |
4b4deea2 TT |
634 | && EQ (oldlist, BVAR (current_buffer, undo_list))) |
635 | BVAR (current_buffer, undo_list) | |
636 | = Fcons (list3 (Qapply, Qcdr, Qnil), BVAR (current_buffer, undo_list)); | |
4ac03187 | 637 | |
de65837b | 638 | UNGCPRO; |
f87a68b3 | 639 | return unbind_to (count, list); |
c6953be1 | 640 | } |
6887bce5 | 641 | \f |
dfcf069d | 642 | void |
971de7fb | 643 | syms_of_undo (void) |
c6953be1 | 644 | { |
d67b4f80 | 645 | Qinhibit_read_only = intern_c_string ("inhibit-read-only"); |
f87a68b3 RS |
646 | staticpro (&Qinhibit_read_only); |
647 | ||
d67b4f80 | 648 | Qapply = intern_c_string ("apply"); |
49be18c9 KS |
649 | staticpro (&Qapply); |
650 | ||
c58632fc RS |
651 | pending_boundary = Qnil; |
652 | staticpro (&pending_boundary); | |
653 | ||
4591d6cb SM |
654 | last_undo_buffer = NULL; |
655 | last_boundary_buffer = NULL; | |
656 | ||
c6953be1 JB |
657 | defsubr (&Sprimitive_undo); |
658 | defsubr (&Sundo_boundary); | |
137e23ea | 659 | |
29208e82 | 660 | DEFVAR_INT ("undo-limit", undo_limit, |
137e23ea RS |
661 | doc: /* Keep no more undo information once it exceeds this size. |
662 | This limit is applied when garbage collection happens. | |
663 | When a previous command increases the total undo list size past this | |
664 | value, the earlier commands that came before it are forgotten. | |
665 | ||
666 | The size is counted as the number of bytes occupied, | |
667 | which includes both saved text and other data. */); | |
2159bd06 | 668 | undo_limit = 80000; |
137e23ea | 669 | |
29208e82 | 670 | DEFVAR_INT ("undo-strong-limit", undo_strong_limit, |
137e23ea RS |
671 | doc: /* Don't keep more than this much size of undo information. |
672 | This limit is applied when garbage collection happens. | |
673 | When a previous command increases the total undo list size past this | |
674 | value, that command and the earlier commands that came before it are forgotten. | |
675 | However, the most recent buffer-modifying command's undo info | |
676 | is never discarded for this reason. | |
677 | ||
678 | The size is counted as the number of bytes occupied, | |
679 | which includes both saved text and other data. */); | |
2159bd06 | 680 | undo_strong_limit = 120000; |
137e23ea | 681 | |
29208e82 | 682 | DEFVAR_LISP ("undo-outer-limit", Vundo_outer_limit, |
137e23ea RS |
683 | doc: /* Outer limit on size of undo information for one command. |
684 | At garbage collection time, if the current command has produced | |
62d776fd LT |
685 | more than this much undo information, it discards the info and displays |
686 | a warning. This is a last-ditch limit to prevent memory overflow. | |
137e23ea | 687 | |
62d776fd LT |
688 | The size is counted as the number of bytes occupied, which includes |
689 | both saved text and other data. A value of nil means no limit. In | |
690 | this case, accumulating one huge undo entry could make Emacs crash as | |
691 | a result of memory overflow. | |
137e23ea RS |
692 | |
693 | In fact, this calls the function which is the value of | |
694 | `undo-outer-limit-function' with one argument, the size. | |
695 | The text above describes the behavior of the function | |
696 | that variable usually specifies. */); | |
2159bd06 | 697 | Vundo_outer_limit = make_number (12000000); |
137e23ea | 698 | |
29208e82 | 699 | DEFVAR_LISP ("undo-outer-limit-function", Vundo_outer_limit_function, |
137e23ea RS |
700 | doc: /* Function to call when an undo list exceeds `undo-outer-limit'. |
701 | This function is called with one argument, the current undo list size | |
702 | for the most recent command (since the last undo boundary). | |
703 | If the function returns t, that means truncation has been fully handled. | |
704 | If it returns nil, the other forms of truncation are done. | |
705 | ||
706 | Garbage collection is inhibited around the call to this function, | |
707 | so it must make sure not to do a lot of consing. */); | |
708 | Vundo_outer_limit_function = Qnil; | |
8abe0f97 | 709 | |
29208e82 | 710 | DEFVAR_BOOL ("undo-inhibit-record-point", undo_inhibit_record_point, |
8abe0f97 MR |
711 | doc: /* Non-nil means do not record `point' in `buffer-undo-list'. */); |
712 | undo_inhibit_record_point = 0; | |
c6953be1 | 713 | } |