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c6953be1 | 1 | /* undo handling for GNU Emacs. |
acaf905b | 2 | Copyright (C) 1990, 1993-1994, 2000-2012 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> |
0328b6de | 21 | |
c6953be1 | 22 | #include "lisp.h" |
e5560ff7 | 23 | #include "character.h" |
c6953be1 | 24 | #include "buffer.h" |
4e665715 | 25 | #include "commands.h" |
91e25f5e | 26 | #include "window.h" |
c6953be1 JB |
27 | |
28 | /* Last buffer for which undo information was recorded. */ | |
4591d6cb | 29 | /* BEWARE: This is not traced by the GC, so never dereference it! */ |
2b96acb7 | 30 | static struct buffer *last_undo_buffer; |
4591d6cb SM |
31 | |
32 | /* Position of point last time we inserted a boundary. */ | |
2b96acb7 | 33 | static struct buffer *last_boundary_buffer; |
d311d28c | 34 | static ptrdiff_t last_boundary_position; |
c6953be1 | 35 | |
f87a68b3 RS |
36 | Lisp_Object Qinhibit_read_only; |
37 | ||
49be18c9 KS |
38 | /* Marker for function call undo list elements. */ |
39 | ||
40 | Lisp_Object Qapply; | |
41 | ||
c58632fc RS |
42 | /* The first time a command records something for undo. |
43 | it also allocates the undo-boundary object | |
44 | which will be added to the list at the end of the command. | |
45 | This ensures we can't run out of space while trying to make | |
46 | an undo-boundary. */ | |
2b96acb7 | 47 | static Lisp_Object pending_boundary; |
c58632fc | 48 | |
6396140a | 49 | /* Record point as it was at beginning of this command (if necessary) |
8abe0f97 | 50 | and prepare the undo info for recording a change. |
6396140a SM |
51 | PT is the position of point that will naturally occur as a result of the |
52 | undo record that will be added just after this command terminates. */ | |
c6953be1 | 53 | |
6396140a | 54 | static void |
d311d28c | 55 | record_point (ptrdiff_t pt) |
c6953be1 | 56 | { |
6396140a | 57 | int at_boundary; |
bdbe6f28 | 58 | |
4591d6cb | 59 | /* Don't record position of pt when undo_inhibit_record_point holds. */ |
8abe0f97 MR |
60 | if (undo_inhibit_record_point) |
61 | return; | |
62 | ||
c58632fc RS |
63 | /* Allocate a cons cell to be the undo boundary after this command. */ |
64 | if (NILP (pending_boundary)) | |
65 | pending_boundary = Fcons (Qnil, Qnil); | |
66 | ||
3ecc1163 MR |
67 | if ((current_buffer != last_undo_buffer) |
68 | /* Don't call Fundo_boundary for the first change. Otherwise we | |
69 | risk overwriting last_boundary_position in Fundo_boundary with | |
70 | PT of the current buffer and as a consequence not insert an | |
71 | undo boundary because last_boundary_position will equal pt in | |
72 | the test at the end of the present function (Bug#731). */ | |
73 | && (MODIFF > SAVE_MODIFF)) | |
c6953be1 | 74 | Fundo_boundary (); |
4591d6cb | 75 | last_undo_buffer = current_buffer; |
c6953be1 | 76 | |
4b4deea2 | 77 | if (CONSP (BVAR (current_buffer, undo_list))) |
6396140a SM |
78 | { |
79 | /* Set AT_BOUNDARY to 1 only when we have nothing other than | |
80 | marker adjustment before undo boundary. */ | |
81 | ||
4b4deea2 | 82 | Lisp_Object tail = BVAR (current_buffer, undo_list), elt; |
6396140a SM |
83 | |
84 | while (1) | |
85 | { | |
86 | if (NILP (tail)) | |
87 | elt = Qnil; | |
88 | else | |
89 | elt = XCAR (tail); | |
90 | if (NILP (elt) || ! (CONSP (elt) && MARKERP (XCAR (elt)))) | |
91 | break; | |
92 | tail = XCDR (tail); | |
93 | } | |
94 | at_boundary = NILP (elt); | |
95 | } | |
96 | else | |
97 | at_boundary = 1; | |
98 | ||
ad9cdce4 | 99 | if (MODIFF <= SAVE_MODIFF) |
c6953be1 JB |
100 | record_first_change (); |
101 | ||
177c0ea7 | 102 | /* If we are just after an undo boundary, and |
6396140a SM |
103 | point wasn't at start of deleted range, record where it was. */ |
104 | if (at_boundary | |
4591d6cb SM |
105 | && current_buffer == last_boundary_buffer |
106 | && last_boundary_position != pt) | |
39eb03f1 PE |
107 | bset_undo_list (current_buffer, |
108 | Fcons (make_number (last_boundary_position), | |
109 | BVAR (current_buffer, undo_list))); | |
6396140a SM |
110 | } |
111 | ||
112 | /* Record an insertion that just happened or is about to happen, | |
113 | for LENGTH characters at position BEG. | |
114 | (It is possible to record an insertion before or after the fact | |
115 | because we don't need to record the contents.) */ | |
116 | ||
117 | void | |
d311d28c | 118 | record_insert (ptrdiff_t beg, ptrdiff_t length) |
6396140a SM |
119 | { |
120 | Lisp_Object lbeg, lend; | |
121 | ||
4b4deea2 | 122 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
6396140a SM |
123 | return; |
124 | ||
125 | record_point (beg); | |
126 | ||
c6953be1 JB |
127 | /* If this is following another insertion and consecutive with it |
128 | in the buffer, combine the two. */ | |
4b4deea2 | 129 | if (CONSP (BVAR (current_buffer, undo_list))) |
c6953be1 JB |
130 | { |
131 | Lisp_Object elt; | |
4b4deea2 | 132 | elt = XCAR (BVAR (current_buffer, undo_list)); |
38c0d37c | 133 | if (CONSP (elt) |
c1d497be KR |
134 | && INTEGERP (XCAR (elt)) |
135 | && INTEGERP (XCDR (elt)) | |
136 | && XINT (XCDR (elt)) == beg) | |
c6953be1 | 137 | { |
f3fbd155 | 138 | XSETCDR (elt, make_number (beg + length)); |
c6953be1 JB |
139 | return; |
140 | } | |
141 | } | |
142 | ||
53480e99 KH |
143 | XSETFASTINT (lbeg, beg); |
144 | XSETINT (lend, beg + length); | |
39eb03f1 PE |
145 | bset_undo_list (current_buffer, |
146 | Fcons (Fcons (lbeg, lend), BVAR (current_buffer, undo_list))); | |
c6953be1 JB |
147 | } |
148 | ||
149 | /* Record that a deletion is about to take place, | |
e928d437 | 150 | of the characters in STRING, at location BEG. */ |
c6953be1 | 151 | |
ff1aa840 | 152 | void |
d311d28c | 153 | record_delete (ptrdiff_t beg, Lisp_Object string) |
c6953be1 | 154 | { |
e928d437 | 155 | Lisp_Object sbeg; |
c6953be1 | 156 | |
4b4deea2 | 157 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
bdbe6f28 RS |
158 | return; |
159 | ||
d5db4077 | 160 | if (PT == beg + SCHARS (string)) |
cbc1b668 | 161 | { |
6396140a SM |
162 | XSETINT (sbeg, -beg); |
163 | record_point (PT); | |
cbc1b668 KH |
164 | } |
165 | else | |
6396140a SM |
166 | { |
167 | XSETFASTINT (sbeg, beg); | |
168 | record_point (beg); | |
169 | } | |
350bce56 | 170 | |
39eb03f1 PE |
171 | bset_undo_list |
172 | (current_buffer, | |
173 | Fcons (Fcons (string, sbeg), BVAR (current_buffer, undo_list))); | |
c6953be1 JB |
174 | } |
175 | ||
714bced9 RS |
176 | /* Record the fact that MARKER is about to be adjusted by ADJUSTMENT. |
177 | This is done only when a marker points within text being deleted, | |
178 | because that's the only case where an automatic marker adjustment | |
179 | won't be inverted automatically by undoing the buffer modification. */ | |
180 | ||
ff1aa840 | 181 | void |
d311d28c | 182 | record_marker_adjustment (Lisp_Object marker, ptrdiff_t adjustment) |
714bced9 | 183 | { |
4b4deea2 | 184 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
714bced9 RS |
185 | return; |
186 | ||
187 | /* Allocate a cons cell to be the undo boundary after this command. */ | |
188 | if (NILP (pending_boundary)) | |
189 | pending_boundary = Fcons (Qnil, Qnil); | |
190 | ||
4591d6cb | 191 | if (current_buffer != last_undo_buffer) |
714bced9 | 192 | Fundo_boundary (); |
4591d6cb | 193 | last_undo_buffer = current_buffer; |
714bced9 | 194 | |
39eb03f1 PE |
195 | bset_undo_list |
196 | (current_buffer, | |
197 | Fcons (Fcons (marker, make_number (adjustment)), | |
198 | BVAR (current_buffer, undo_list))); | |
714bced9 RS |
199 | } |
200 | ||
c6953be1 JB |
201 | /* Record that a replacement is about to take place, |
202 | for LENGTH characters at location BEG. | |
e928d437 | 203 | The replacement must not change the number of characters. */ |
c6953be1 | 204 | |
ff1aa840 | 205 | void |
d311d28c | 206 | record_change (ptrdiff_t beg, ptrdiff_t length) |
c6953be1 | 207 | { |
e928d437 | 208 | record_delete (beg, make_buffer_string (beg, beg + length, 1)); |
c6953be1 JB |
209 | record_insert (beg, length); |
210 | } | |
211 | \f | |
212 | /* Record that an unmodified buffer is about to be changed. | |
213 | Record the file modification date so that when undoing this entry | |
214 | we can tell whether it is obsolete because the file was saved again. */ | |
215 | ||
90dd3e4f | 216 | void |
971de7fb | 217 | record_first_change (void) |
c6953be1 | 218 | { |
ad9cdce4 | 219 | struct buffer *base_buffer = current_buffer; |
0736cafe | 220 | |
4b4deea2 | 221 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
0736cafe RS |
222 | return; |
223 | ||
4591d6cb | 224 | if (current_buffer != last_undo_buffer) |
0736cafe | 225 | Fundo_boundary (); |
4591d6cb | 226 | last_undo_buffer = current_buffer; |
0736cafe | 227 | |
ad9cdce4 RS |
228 | if (base_buffer->base_buffer) |
229 | base_buffer = base_buffer->base_buffer; | |
230 | ||
39eb03f1 PE |
231 | bset_undo_list |
232 | (current_buffer, | |
233 | Fcons (Fcons (Qt, make_lisp_time (base_buffer->modtime)), | |
234 | BVAR (current_buffer, undo_list))); | |
c6953be1 JB |
235 | } |
236 | ||
da9319d5 RS |
237 | /* Record a change in property PROP (whose old value was VAL) |
238 | for LENGTH characters starting at position BEG in BUFFER. */ | |
239 | ||
90dd3e4f | 240 | void |
d311d28c | 241 | record_property_change (ptrdiff_t beg, ptrdiff_t length, |
c8a66ab8 EZ |
242 | Lisp_Object prop, Lisp_Object value, |
243 | Lisp_Object buffer) | |
da9319d5 RS |
244 | { |
245 | Lisp_Object lbeg, lend, entry; | |
4591d6cb | 246 | struct buffer *obuf = current_buffer, *buf = XBUFFER (buffer); |
da9319d5 RS |
247 | int boundary = 0; |
248 | ||
4b4deea2 | 249 | if (EQ (BVAR (buf, undo_list), Qt)) |
bdbe6f28 RS |
250 | return; |
251 | ||
c58632fc RS |
252 | /* Allocate a cons cell to be the undo boundary after this command. */ |
253 | if (NILP (pending_boundary)) | |
254 | pending_boundary = Fcons (Qnil, Qnil); | |
255 | ||
4591d6cb | 256 | if (buf != last_undo_buffer) |
da9319d5 | 257 | boundary = 1; |
4591d6cb | 258 | last_undo_buffer = buf; |
da9319d5 | 259 | |
da9319d5 | 260 | /* Switch temporarily to the buffer that was changed. */ |
4591d6cb | 261 | current_buffer = buf; |
da9319d5 RS |
262 | |
263 | if (boundary) | |
264 | Fundo_boundary (); | |
265 | ||
ad9cdce4 | 266 | if (MODIFF <= SAVE_MODIFF) |
da9319d5 RS |
267 | record_first_change (); |
268 | ||
552bdbcf KH |
269 | XSETINT (lbeg, beg); |
270 | XSETINT (lend, beg + length); | |
da9319d5 | 271 | entry = Fcons (Qnil, Fcons (prop, Fcons (value, Fcons (lbeg, lend)))); |
39eb03f1 PE |
272 | bset_undo_list (current_buffer, |
273 | Fcons (entry, BVAR (current_buffer, undo_list))); | |
da9319d5 RS |
274 | |
275 | current_buffer = obuf; | |
276 | } | |
277 | ||
a7ca3326 | 278 | DEFUN ("undo-boundary", Fundo_boundary, Sundo_boundary, 0, 0, 0, |
8c1a1077 PJ |
279 | doc: /* Mark a boundary between units of undo. |
280 | An undo command will stop at this point, | |
281 | but another undo command will undo to the previous boundary. */) | |
5842a27b | 282 | (void) |
c6953be1 JB |
283 | { |
284 | Lisp_Object tem; | |
4b4deea2 | 285 | if (EQ (BVAR (current_buffer, undo_list), Qt)) |
c6953be1 | 286 | return Qnil; |
4b4deea2 | 287 | tem = Fcar (BVAR (current_buffer, undo_list)); |
265a9e55 | 288 | if (!NILP (tem)) |
c58632fc RS |
289 | { |
290 | /* One way or another, cons nil onto the front of the undo list. */ | |
291 | if (!NILP (pending_boundary)) | |
292 | { | |
293 | /* If we have preallocated the cons cell to use here, | |
294 | use that one. */ | |
4b4deea2 | 295 | XSETCDR (pending_boundary, BVAR (current_buffer, undo_list)); |
39eb03f1 | 296 | bset_undo_list (current_buffer, pending_boundary); |
c58632fc RS |
297 | pending_boundary = Qnil; |
298 | } | |
299 | else | |
39eb03f1 PE |
300 | bset_undo_list (current_buffer, |
301 | Fcons (Qnil, BVAR (current_buffer, undo_list))); | |
c58632fc | 302 | } |
4591d6cb SM |
303 | last_boundary_position = PT; |
304 | last_boundary_buffer = current_buffer; | |
c6953be1 JB |
305 | return Qnil; |
306 | } | |
307 | ||
308 | /* At garbage collection time, make an undo list shorter at the end, | |
137e23ea RS |
309 | returning the truncated list. How this is done depends on the |
310 | variables undo-limit, undo-strong-limit and undo-outer-limit. | |
311 | In some cases this works by calling undo-outer-limit-function. */ | |
312 | ||
313 | void | |
971de7fb | 314 | truncate_undo_list (struct buffer *b) |
c6953be1 | 315 | { |
137e23ea | 316 | Lisp_Object list; |
c6953be1 | 317 | Lisp_Object prev, next, last_boundary; |
d311d28c | 318 | EMACS_INT size_so_far = 0; |
c6953be1 | 319 | |
137e23ea RS |
320 | /* Make sure that calling undo-outer-limit-function |
321 | won't cause another GC. */ | |
d311d28c | 322 | ptrdiff_t count = inhibit_garbage_collection (); |
137e23ea RS |
323 | |
324 | /* Make the buffer current to get its local values of variables such | |
325 | as undo_limit. Also so that Vundo_outer_limit_function can | |
326 | tell which buffer to operate on. */ | |
66322887 | 327 | record_unwind_current_buffer (); |
137e23ea RS |
328 | set_buffer_internal (b); |
329 | ||
4b4deea2 | 330 | list = BVAR (b, undo_list); |
137e23ea | 331 | |
c6953be1 JB |
332 | prev = Qnil; |
333 | next = list; | |
334 | last_boundary = Qnil; | |
335 | ||
137e23ea | 336 | /* If the first element is an undo boundary, skip past it. */ |
c1d497be | 337 | if (CONSP (next) && NILP (XCAR (next))) |
c6953be1 JB |
338 | { |
339 | /* Add in the space occupied by this element and its chain link. */ | |
340 | size_so_far += sizeof (struct Lisp_Cons); | |
341 | ||
342 | /* Advance to next element. */ | |
343 | prev = next; | |
c1d497be | 344 | next = XCDR (next); |
c6953be1 | 345 | } |
e3d5ca1e | 346 | |
137e23ea RS |
347 | /* Always preserve at least the most recent undo record |
348 | unless it is really horribly big. | |
349 | ||
350 | Skip, skip, skip the undo, skip, skip, skip the undo, | |
351 | Skip, skip, skip the undo, skip to the undo bound'ry. */ | |
352 | ||
c1d497be | 353 | while (CONSP (next) && ! NILP (XCAR (next))) |
c6953be1 JB |
354 | { |
355 | Lisp_Object elt; | |
c1d497be | 356 | elt = XCAR (next); |
c6953be1 JB |
357 | |
358 | /* Add in the space occupied by this element and its chain link. */ | |
359 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 360 | if (CONSP (elt)) |
c6953be1 JB |
361 | { |
362 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 363 | if (STRINGP (XCAR (elt))) |
c6953be1 | 364 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 365 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
366 | } |
367 | ||
368 | /* Advance to next element. */ | |
369 | prev = next; | |
c1d497be | 370 | next = XCDR (next); |
c6953be1 | 371 | } |
e3d5ca1e | 372 | |
137e23ea RS |
373 | /* If by the first boundary we have already passed undo_outer_limit, |
374 | we're heading for memory full, so offer to clear out the list. */ | |
81c1cf71 RS |
375 | if (INTEGERP (Vundo_outer_limit) |
376 | && size_so_far > XINT (Vundo_outer_limit) | |
137e23ea RS |
377 | && !NILP (Vundo_outer_limit_function)) |
378 | { | |
4591d6cb SM |
379 | Lisp_Object tem; |
380 | struct buffer *temp = last_undo_buffer; | |
137e23ea RS |
381 | |
382 | /* Normally the function this calls is undo-outer-limit-truncate. */ | |
88fde92a KR |
383 | tem = call1 (Vundo_outer_limit_function, make_number (size_so_far)); |
384 | if (! NILP (tem)) | |
137e23ea RS |
385 | { |
386 | /* The function is responsible for making | |
387 | any desired changes in buffer-undo-list. */ | |
388 | unbind_to (count, Qnil); | |
389 | return; | |
390 | } | |
391 | /* That function probably used the minibuffer, and if so, that | |
392 | changed last_undo_buffer. Change it back so that we don't | |
393 | force next change to make an undo boundary here. */ | |
394 | last_undo_buffer = temp; | |
395 | } | |
396 | ||
38c0d37c | 397 | if (CONSP (next)) |
c6953be1 JB |
398 | last_boundary = prev; |
399 | ||
137e23ea | 400 | /* Keep additional undo data, if it fits in the limits. */ |
38c0d37c | 401 | while (CONSP (next)) |
c6953be1 JB |
402 | { |
403 | Lisp_Object elt; | |
c1d497be | 404 | elt = XCAR (next); |
c6953be1 JB |
405 | |
406 | /* When we get to a boundary, decide whether to truncate | |
137e23ea | 407 | either before or after it. The lower threshold, undo_limit, |
c6953be1 | 408 | tells us to truncate after it. If its size pushes past |
137e23ea | 409 | the higher threshold undo_strong_limit, we truncate before it. */ |
265a9e55 | 410 | if (NILP (elt)) |
c6953be1 | 411 | { |
137e23ea | 412 | if (size_so_far > undo_strong_limit) |
c6953be1 JB |
413 | break; |
414 | last_boundary = prev; | |
137e23ea | 415 | if (size_so_far > undo_limit) |
c6953be1 JB |
416 | break; |
417 | } | |
418 | ||
419 | /* Add in the space occupied by this element and its chain link. */ | |
420 | size_so_far += sizeof (struct Lisp_Cons); | |
38c0d37c | 421 | if (CONSP (elt)) |
c6953be1 JB |
422 | { |
423 | size_so_far += sizeof (struct Lisp_Cons); | |
c1d497be | 424 | if (STRINGP (XCAR (elt))) |
c6953be1 | 425 | size_so_far += (sizeof (struct Lisp_String) - 1 |
d5db4077 | 426 | + SCHARS (XCAR (elt))); |
c6953be1 JB |
427 | } |
428 | ||
429 | /* Advance to next element. */ | |
430 | prev = next; | |
c1d497be | 431 | next = XCDR (next); |
c6953be1 JB |
432 | } |
433 | ||
434 | /* If we scanned the whole list, it is short enough; don't change it. */ | |
265a9e55 | 435 | if (NILP (next)) |
137e23ea | 436 | ; |
c6953be1 | 437 | /* Truncate at the boundary where we decided to truncate. */ |
137e23ea RS |
438 | else if (!NILP (last_boundary)) |
439 | XSETCDR (last_boundary, Qnil); | |
440 | /* There's nothing we decided to keep, so clear it out. */ | |
c6953be1 | 441 | else |
39eb03f1 | 442 | bset_undo_list (b, Qnil); |
137e23ea RS |
443 | |
444 | unbind_to (count, Qnil); | |
c6953be1 | 445 | } |
71873e2b | 446 | |
845ca893 PE |
447 | static _Noreturn void |
448 | user_error (const char *msg) | |
71873e2b SM |
449 | { |
450 | xsignal1 (Quser_error, build_string (msg)); | |
451 | } | |
452 | ||
c6953be1 JB |
453 | \f |
454 | DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0, | |
8c1a1077 PJ |
455 | doc: /* Undo N records from the front of the list LIST. |
456 | Return what remains of the list. */) | |
5842a27b | 457 | (Lisp_Object n, Lisp_Object list) |
c6953be1 | 458 | { |
de65837b KH |
459 | struct gcpro gcpro1, gcpro2; |
460 | Lisp_Object next; | |
d311d28c PE |
461 | ptrdiff_t count = SPECPDL_INDEX (); |
462 | register EMACS_INT arg; | |
4ac03187 KS |
463 | Lisp_Object oldlist; |
464 | int did_apply = 0; | |
177c0ea7 | 465 | |
c6953be1 JB |
466 | #if 0 /* This is a good feature, but would make undo-start |
467 | unable to do what is expected. */ | |
468 | Lisp_Object tem; | |
469 | ||
470 | /* If the head of the list is a boundary, it is the boundary | |
471 | preceding this command. Get rid of it and don't count it. */ | |
472 | tem = Fcar (list); | |
265a9e55 | 473 | if (NILP (tem)) |
c6953be1 JB |
474 | list = Fcdr (list); |
475 | #endif | |
476 | ||
b7826503 | 477 | CHECK_NUMBER (n); |
de65837b KH |
478 | arg = XINT (n); |
479 | next = Qnil; | |
480 | GCPRO2 (next, list); | |
4ac03187 KS |
481 | /* I don't think we need to gcpro oldlist, as we use it only |
482 | to check for EQ. ++kfs */ | |
de65837b | 483 | |
38d56be3 GM |
484 | /* In a writable buffer, enable undoing read-only text that is so |
485 | because of text properties. */ | |
4b4deea2 | 486 | if (NILP (BVAR (current_buffer, read_only))) |
f87a68b3 RS |
487 | specbind (Qinhibit_read_only, Qt); |
488 | ||
8c757fd7 GM |
489 | /* Don't let `intangible' properties interfere with undo. */ |
490 | specbind (Qinhibit_point_motion_hooks, Qt); | |
491 | ||
4b4deea2 | 492 | oldlist = BVAR (current_buffer, undo_list); |
4ac03187 | 493 | |
c6953be1 JB |
494 | while (arg > 0) |
495 | { | |
c3b09bbf | 496 | while (CONSP (list)) |
c6953be1 | 497 | { |
c3b09bbf SM |
498 | next = XCAR (list); |
499 | list = XCDR (list); | |
350bce56 | 500 | /* Exit inner loop at undo boundary. */ |
265a9e55 | 501 | if (NILP (next)) |
c6953be1 | 502 | break; |
350bce56 | 503 | /* Handle an integer by setting point to that value. */ |
38c0d37c | 504 | if (INTEGERP (next)) |
350bce56 | 505 | SET_PT (clip_to_bounds (BEGV, XINT (next), ZV)); |
38c0d37c | 506 | else if (CONSP (next)) |
c6953be1 | 507 | { |
350bce56 RS |
508 | Lisp_Object car, cdr; |
509 | ||
c3b09bbf SM |
510 | car = XCAR (next); |
511 | cdr = XCDR (next); | |
350bce56 | 512 | if (EQ (car, Qt)) |
c6953be1 | 513 | { |
d35af63c PE |
514 | /* Element (t . TIME) records previous modtime. |
515 | Preserve any flag of NONEXISTENT_MODTIME_NSECS or | |
516 | UNKNOWN_MODTIME_NSECS. */ | |
ad9cdce4 | 517 | struct buffer *base_buffer = current_buffer; |
d35af63c PE |
518 | EMACS_TIME mod_time; |
519 | ||
520 | if (CONSP (cdr) | |
521 | && CONSP (XCDR (cdr)) | |
522 | && CONSP (XCDR (XCDR (cdr))) | |
523 | && CONSP (XCDR (XCDR (XCDR (cdr)))) | |
524 | && INTEGERP (XCAR (XCDR (XCDR (XCDR (cdr))))) | |
525 | && XINT (XCAR (XCDR (XCDR (XCDR (cdr))))) < 0) | |
e9a9ae03 PE |
526 | mod_time = |
527 | (make_emacs_time | |
528 | (0, XINT (XCAR (XCDR (XCDR (XCDR (cdr))))) / 1000)); | |
d35af63c | 529 | else |
31571fd7 | 530 | mod_time = lisp_time_argument (cdr); |
ad9cdce4 RS |
531 | |
532 | if (current_buffer->base_buffer) | |
533 | base_buffer = current_buffer->base_buffer; | |
534 | ||
350bce56 RS |
535 | /* If this records an obsolete save |
536 | (not matching the actual disk file) | |
537 | then don't mark unmodified. */ | |
d35af63c | 538 | if (EMACS_TIME_NE (mod_time, base_buffer->modtime)) |
103dcb38 | 539 | continue; |
e6dd6080 | 540 | #ifdef CLASH_DETECTION |
350bce56 | 541 | Funlock_buffer (); |
e6dd6080 | 542 | #endif /* CLASH_DETECTION */ |
350bce56 | 543 | Fset_buffer_modified_p (Qnil); |
c6953be1 | 544 | } |
d8552b2f | 545 | else if (EQ (car, Qnil)) |
da9319d5 | 546 | { |
6887bce5 | 547 | /* Element (nil PROP VAL BEG . END) is property change. */ |
da9319d5 RS |
548 | Lisp_Object beg, end, prop, val; |
549 | ||
550 | prop = Fcar (cdr); | |
551 | cdr = Fcdr (cdr); | |
552 | val = Fcar (cdr); | |
553 | cdr = Fcdr (cdr); | |
554 | beg = Fcar (cdr); | |
555 | end = Fcdr (cdr); | |
556 | ||
9e568684 | 557 | if (XINT (beg) < BEGV || XINT (end) > ZV) |
71873e2b | 558 | user_error ("Changes to be undone are outside visible portion of buffer"); |
da9319d5 RS |
559 | Fput_text_property (beg, end, prop, val, Qnil); |
560 | } | |
38c0d37c | 561 | else if (INTEGERP (car) && INTEGERP (cdr)) |
c6953be1 | 562 | { |
350bce56 | 563 | /* Element (BEG . END) means range was inserted. */ |
350bce56 RS |
564 | |
565 | if (XINT (car) < BEGV | |
566 | || XINT (cdr) > ZV) | |
71873e2b | 567 | user_error ("Changes to be undone are outside visible portion of buffer"); |
f28f04cc RS |
568 | /* Set point first thing, so that undoing this undo |
569 | does not send point back to where it is now. */ | |
350bce56 | 570 | Fgoto_char (car); |
f28f04cc | 571 | Fdelete_region (car, cdr); |
350bce56 | 572 | } |
49be18c9 | 573 | else if (EQ (car, Qapply)) |
6887bce5 | 574 | { |
3419757d | 575 | /* Element (apply FUN . ARGS) means call FUN to undo. */ |
a7a39468 KS |
576 | struct buffer *save_buffer = current_buffer; |
577 | ||
49be18c9 | 578 | car = Fcar (cdr); |
3419757d | 579 | cdr = Fcdr (cdr); |
49be18c9 KS |
580 | if (INTEGERP (car)) |
581 | { | |
3419757d SM |
582 | /* Long format: (apply DELTA START END FUN . ARGS). */ |
583 | Lisp_Object delta = car; | |
584 | Lisp_Object start = Fcar (cdr); | |
585 | Lisp_Object end = Fcar (Fcdr (cdr)); | |
586 | Lisp_Object start_mark = Fcopy_marker (start, Qnil); | |
587 | Lisp_Object end_mark = Fcopy_marker (end, Qt); | |
588 | ||
589 | cdr = Fcdr (Fcdr (cdr)); | |
590 | apply1 (Fcar (cdr), Fcdr (cdr)); | |
591 | ||
592 | /* Check that the function did what the entry said it | |
593 | would do. */ | |
594 | if (!EQ (start, Fmarker_position (start_mark)) | |
595 | || (XINT (delta) + XINT (end) | |
596 | != marker_position (end_mark))) | |
597 | error ("Changes to be undone by function different than announced"); | |
598 | Fset_marker (start_mark, Qnil, Qnil); | |
599 | Fset_marker (end_mark, Qnil, Qnil); | |
49be18c9 | 600 | } |
3419757d SM |
601 | else |
602 | apply1 (car, cdr); | |
a7a39468 KS |
603 | |
604 | if (save_buffer != current_buffer) | |
605 | error ("Undo function switched buffer"); | |
4ac03187 | 606 | did_apply = 1; |
6887bce5 | 607 | } |
38c0d37c | 608 | else if (STRINGP (car) && INTEGERP (cdr)) |
350bce56 RS |
609 | { |
610 | /* Element (STRING . POS) means STRING was deleted. */ | |
611 | Lisp_Object membuf; | |
c8a66ab8 | 612 | EMACS_INT pos = XINT (cdr); |
350bce56 RS |
613 | |
614 | membuf = car; | |
615 | if (pos < 0) | |
616 | { | |
617 | if (-pos < BEGV || -pos > ZV) | |
71873e2b | 618 | user_error ("Changes to be undone are outside visible portion of buffer"); |
350bce56 RS |
619 | SET_PT (-pos); |
620 | Finsert (1, &membuf); | |
621 | } | |
622 | else | |
623 | { | |
624 | if (pos < BEGV || pos > ZV) | |
71873e2b | 625 | user_error ("Changes to be undone are outside visible portion of buffer"); |
350bce56 RS |
626 | SET_PT (pos); |
627 | ||
b2adc409 RS |
628 | /* Now that we record marker adjustments |
629 | (caused by deletion) for undo, | |
630 | we should always insert after markers, | |
631 | so that undoing the marker adjustments | |
632 | put the markers back in the right place. */ | |
633 | Finsert (1, &membuf); | |
350bce56 RS |
634 | SET_PT (pos); |
635 | } | |
c6953be1 | 636 | } |
714bced9 RS |
637 | else if (MARKERP (car) && INTEGERP (cdr)) |
638 | { | |
639 | /* (MARKER . INTEGER) means a marker MARKER | |
640 | was adjusted by INTEGER. */ | |
641 | if (XMARKER (car)->buffer) | |
642 | Fset_marker (car, | |
643 | make_number (marker_position (car) - XINT (cdr)), | |
644 | Fmarker_buffer (car)); | |
645 | } | |
c6953be1 JB |
646 | } |
647 | } | |
648 | arg--; | |
649 | } | |
650 | ||
4ac03187 KS |
651 | |
652 | /* Make sure an apply entry produces at least one undo entry, | |
653 | so the test in `undo' for continuing an undo series | |
654 | will work right. */ | |
655 | if (did_apply | |
4b4deea2 | 656 | && EQ (oldlist, BVAR (current_buffer, undo_list))) |
39eb03f1 PE |
657 | bset_undo_list |
658 | (current_buffer, | |
659 | Fcons (list3 (Qapply, Qcdr, Qnil), BVAR (current_buffer, undo_list))); | |
4ac03187 | 660 | |
de65837b | 661 | UNGCPRO; |
f87a68b3 | 662 | return unbind_to (count, list); |
c6953be1 | 663 | } |
6887bce5 | 664 | \f |
dfcf069d | 665 | void |
971de7fb | 666 | syms_of_undo (void) |
c6953be1 | 667 | { |
cd3520a4 JB |
668 | DEFSYM (Qinhibit_read_only, "inhibit-read-only"); |
669 | DEFSYM (Qapply, "apply"); | |
49be18c9 | 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 | 679 | |
29208e82 | 680 | DEFVAR_INT ("undo-limit", undo_limit, |
137e23ea RS |
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. */); | |
2159bd06 | 688 | undo_limit = 80000; |
137e23ea | 689 | |
29208e82 | 690 | DEFVAR_INT ("undo-strong-limit", undo_strong_limit, |
137e23ea RS |
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. */); | |
2159bd06 | 700 | undo_strong_limit = 120000; |
137e23ea | 701 | |
29208e82 | 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. */); | |
2159bd06 | 717 | Vundo_outer_limit = make_number (12000000); |
137e23ea | 718 | |
29208e82 | 719 | DEFVAR_LISP ("undo-outer-limit-function", Vundo_outer_limit_function, |
137e23ea RS |
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 | 729 | |
29208e82 | 730 | DEFVAR_BOOL ("undo-inhibit-record-point", undo_inhibit_record_point, |
8abe0f97 MR |
731 | doc: /* Non-nil means do not record `point' in `buffer-undo-list'. */); |
732 | undo_inhibit_record_point = 0; | |
c6953be1 | 733 | } |