428
+ − 1 /* Markers: examining, setting and killing.
+ − 2 Copyright (C) 1985, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+ − 3
+ − 4 This file is part of XEmacs.
+ − 5
+ − 6 XEmacs is free software; you can redistribute it and/or modify it
+ − 7 under the terms of the GNU General Public License as published by the
+ − 8 Free Software Foundation; either version 2, or (at your option) any
+ − 9 later version.
+ − 10
+ − 11 XEmacs is distributed in the hope that it will be useful, but WITHOUT
+ − 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ − 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ − 14 for more details.
+ − 15
+ − 16 You should have received a copy of the GNU General Public License
+ − 17 along with XEmacs; see the file COPYING. If not, write to
+ − 18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ − 19 Boston, MA 02111-1307, USA. */
+ − 20
+ − 21 /* Synched up with: FSF 19.30. */
+ − 22
+ − 23 /* This file has been Mule-ized. */
+ − 24
+ − 25 /* Note that markers are currently kept in an unordered list.
+ − 26 This means that marker operations may be inefficient if
+ − 27 there are a bunch of markers in the buffer. This probably
+ − 28 won't have a significant impact on redisplay (which uses
+ − 29 markers), but if it does, it wouldn't be too hard to change
+ − 30 to an ordered gap array. (Just copy the code from extents.c.)
+ − 31 */
+ − 32
+ − 33 #include <config.h>
+ − 34 #include "lisp.h"
+ − 35
+ − 36 #include "buffer.h"
+ − 37
+ − 38 static Lisp_Object
+ − 39 mark_marker (Lisp_Object obj)
+ − 40 {
440
+ − 41 Lisp_Marker *marker = XMARKER (obj);
428
+ − 42 Lisp_Object buf;
+ − 43 /* DO NOT mark through the marker's chain.
+ − 44 The buffer's markers chain does not preserve markers from gc;
+ − 45 Instead, markers are removed from the chain when they are freed
+ − 46 by gc.
+ − 47 */
+ − 48 if (!marker->buffer)
+ − 49 return (Qnil);
+ − 50
+ − 51 XSETBUFFER (buf, marker->buffer);
+ − 52 return (buf);
+ − 53 }
+ − 54
+ − 55 static void
+ − 56 print_marker (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
+ − 57 {
440
+ − 58 Lisp_Marker *marker = XMARKER (obj);
428
+ − 59 char buf[200];
+ − 60
+ − 61 if (print_readably)
563
+ − 62 printing_unreadable_object ("#<marker 0x%lx>", (long) marker);
428
+ − 63
+ − 64 write_c_string (GETTEXT ("#<marker "), printcharfun);
+ − 65 if (!marker->buffer)
+ − 66 write_c_string (GETTEXT ("in no buffer"), printcharfun);
+ − 67 else
+ − 68 {
+ − 69 sprintf (buf, "at %ld in ", (long) marker_position (obj));
+ − 70 write_c_string (buf, printcharfun);
+ − 71 print_internal (marker->buffer->name, printcharfun, 0);
+ − 72 }
+ − 73 sprintf (buf, " 0x%lx>", (long) marker);
+ − 74 write_c_string (buf, printcharfun);
+ − 75 }
+ − 76
+ − 77 static int
+ − 78 marker_equal (Lisp_Object obj1, Lisp_Object obj2, int depth)
+ − 79 {
440
+ − 80 Lisp_Marker *marker1 = XMARKER (obj1);
+ − 81 Lisp_Marker *marker2 = XMARKER (obj2);
428
+ − 82
+ − 83 return ((marker1->buffer == marker2->buffer) &&
665
+ − 84 (marker1->membpos == marker2->membpos ||
428
+ − 85 /* All markers pointing nowhere are equal */
+ − 86 !marker1->buffer));
+ − 87 }
+ − 88
+ − 89 static unsigned long
+ − 90 marker_hash (Lisp_Object obj, int depth)
+ − 91 {
+ − 92 unsigned long hash = (unsigned long) XMARKER (obj)->buffer;
+ − 93 if (hash)
665
+ − 94 hash = HASH2 (hash, XMARKER (obj)->membpos);
428
+ − 95 return hash;
+ − 96 }
+ − 97
+ − 98 static const struct lrecord_description marker_description[] = {
440
+ − 99 { XD_LISP_OBJECT, offsetof (Lisp_Marker, next) },
+ − 100 { XD_LISP_OBJECT, offsetof (Lisp_Marker, prev) },
+ − 101 { XD_LISP_OBJECT, offsetof (Lisp_Marker, buffer) },
428
+ − 102 { XD_END }
+ − 103 };
+ − 104
+ − 105 DEFINE_BASIC_LRECORD_IMPLEMENTATION ("marker", marker,
+ − 106 mark_marker, print_marker, 0,
+ − 107 marker_equal, marker_hash, marker_description,
440
+ − 108 Lisp_Marker);
428
+ − 109
+ − 110 /* Operations on markers. */
+ − 111
+ − 112 DEFUN ("marker-buffer", Fmarker_buffer, 1, 1, 0, /*
+ − 113 Return the buffer that MARKER points into, or nil if none.
+ − 114 Return nil if MARKER points into a dead buffer or doesn't point anywhere.
+ − 115 */
+ − 116 (marker))
+ − 117 {
+ − 118 struct buffer *buf;
+ − 119 CHECK_MARKER (marker);
+ − 120 /* Return marker's buffer only if it is not dead. */
+ − 121 if ((buf = XMARKER (marker)->buffer) && BUFFER_LIVE_P (buf))
+ − 122 {
+ − 123 Lisp_Object buffer;
+ − 124 XSETBUFFER (buffer, buf);
+ − 125 return buffer;
+ − 126 }
+ − 127 return Qnil;
+ − 128 }
+ − 129
+ − 130 DEFUN ("marker-position", Fmarker_position, 1, 1, 0, /*
+ − 131 Return the position MARKER points at, as a character number.
+ − 132 Return `nil' if marker doesn't point anywhere.
+ − 133 */
+ − 134 (marker))
+ − 135 {
+ − 136 CHECK_MARKER (marker);
+ − 137 return XMARKER (marker)->buffer ? make_int (marker_position (marker)) : Qnil;
+ − 138 }
+ − 139
+ − 140 #if 0 /* useful debugging function */
+ − 141
+ − 142 static void
+ − 143 check_marker_circularities (struct buffer *buf)
+ − 144 {
440
+ − 145 Lisp_Marker *tortoise, *hare;
428
+ − 146
+ − 147 tortoise = BUF_MARKERS (buf);
+ − 148 hare = tortoise;
+ − 149
+ − 150 if (!tortoise)
+ − 151 return;
+ − 152
+ − 153 while (1)
+ − 154 {
+ − 155 assert (hare->buffer == buf);
+ − 156 hare = hare->next;
+ − 157 if (!hare)
+ − 158 return;
+ − 159 assert (hare->buffer == buf);
+ − 160 hare = hare->next;
+ − 161 if (!hare)
+ − 162 return;
+ − 163 tortoise = tortoise->next;
+ − 164 assert (tortoise != hare);
+ − 165 }
+ − 166 }
+ − 167
+ − 168 #endif
+ − 169
+ − 170 static Lisp_Object
444
+ − 171 set_marker_internal (Lisp_Object marker, Lisp_Object position,
+ − 172 Lisp_Object buffer, int restricted_p)
428
+ − 173 {
665
+ − 174 Charbpos charno;
428
+ − 175 struct buffer *b;
440
+ − 176 Lisp_Marker *m;
428
+ − 177 int point_p;
+ − 178
+ − 179 CHECK_MARKER (marker);
+ − 180
+ − 181 point_p = POINT_MARKER_P (marker);
+ − 182
+ − 183 /* If position is nil or a marker that points nowhere,
+ − 184 make this marker point nowhere. */
444
+ − 185 if (NILP (position) ||
+ − 186 (MARKERP (position) && !XMARKER (position)->buffer))
428
+ − 187 {
+ − 188 if (point_p)
563
+ − 189 invalid_operation ("Can't make point-marker point nowhere",
+ − 190 marker);
428
+ − 191 if (XMARKER (marker)->buffer)
+ − 192 unchain_marker (marker);
+ − 193 return marker;
+ − 194 }
+ − 195
444
+ − 196 CHECK_INT_COERCE_MARKER (position);
428
+ − 197 if (NILP (buffer))
+ − 198 b = current_buffer;
+ − 199 else
+ − 200 {
+ − 201 CHECK_BUFFER (buffer);
+ − 202 b = XBUFFER (buffer);
+ − 203 /* If buffer is dead, set marker to point nowhere. */
+ − 204 if (!BUFFER_LIVE_P (XBUFFER (buffer)))
+ − 205 {
+ − 206 if (point_p)
563
+ − 207 invalid_operation
428
+ − 208 ("Can't move point-marker in a killed buffer", marker);
+ − 209 if (XMARKER (marker)->buffer)
+ − 210 unchain_marker (marker);
+ − 211 return marker;
+ − 212 }
+ − 213 }
+ − 214
444
+ − 215 charno = XINT (position);
428
+ − 216 m = XMARKER (marker);
+ − 217
+ − 218 if (restricted_p)
+ − 219 {
+ − 220 if (charno < BUF_BEGV (b)) charno = BUF_BEGV (b);
+ − 221 if (charno > BUF_ZV (b)) charno = BUF_ZV (b);
+ − 222 }
+ − 223 else
+ − 224 {
+ − 225 if (charno < BUF_BEG (b)) charno = BUF_BEG (b);
+ − 226 if (charno > BUF_Z (b)) charno = BUF_Z (b);
+ − 227 }
+ − 228
+ − 229 if (point_p)
+ − 230 {
+ − 231 #ifndef moving_point_by_moving_its_marker_is_a_bug
+ − 232 BUF_SET_PT (b, charno); /* this will move the marker */
+ − 233 #else /* It's not a feature, so it must be a bug */
563
+ − 234 invalid_operation ("DEBUG: attempt to move point via point-marker",
+ − 235 marker);
428
+ − 236 #endif
+ − 237 }
+ − 238 else
+ − 239 {
665
+ − 240 m->membpos = charbpos_to_membpos (b, charno);
428
+ − 241 }
+ − 242
+ − 243 if (m->buffer != b)
+ − 244 {
+ − 245 if (point_p)
563
+ − 246 invalid_operation ("Can't change buffer of point-marker", marker);
428
+ − 247 if (m->buffer != 0)
+ − 248 unchain_marker (marker);
+ − 249 m->buffer = b;
+ − 250 marker_next (m) = BUF_MARKERS (b);
+ − 251 marker_prev (m) = 0;
+ − 252 if (BUF_MARKERS (b))
+ − 253 marker_prev (BUF_MARKERS (b)) = m;
+ − 254 BUF_MARKERS (b) = m;
+ − 255 }
+ − 256
+ − 257 return marker;
+ − 258 }
+ − 259
+ − 260
+ − 261 DEFUN ("set-marker", Fset_marker, 2, 3, 0, /*
444
+ − 262 Move MARKER to position POSITION in BUFFER.
+ − 263 POSITION can be a marker, an integer or nil. If POSITION is an
+ − 264 integer, make MARKER point before the POSITIONth character in BUFFER.
+ − 265 If POSITION is nil, makes MARKER point nowhere. Then it no longer
+ − 266 slows down editing in any buffer. If POSITION is less than 1, move
+ − 267 MARKER to the beginning of BUFFER. If POSITION is greater than the
+ − 268 size of BUFFER, move MARKER to the end of BUFFER.
428
+ − 269 BUFFER defaults to the current buffer.
444
+ − 270 If this marker was returned by (point-marker t), then changing its
+ − 271 position moves point. You cannot change its buffer or make it point
+ − 272 nowhere.
+ − 273 The return value is MARKER.
428
+ − 274 */
444
+ − 275 (marker, position, buffer))
428
+ − 276 {
444
+ − 277 return set_marker_internal (marker, position, buffer, 0);
428
+ − 278 }
+ − 279
+ − 280
+ − 281 /* This version of Fset_marker won't let the position
+ − 282 be outside the visible part. */
+ − 283 Lisp_Object
444
+ − 284 set_marker_restricted (Lisp_Object marker, Lisp_Object position,
+ − 285 Lisp_Object buffer)
428
+ − 286 {
444
+ − 287 return set_marker_internal (marker, position, buffer, 1);
428
+ − 288 }
+ − 289
+ − 290
+ − 291 /* This is called during garbage collection,
+ − 292 so we must be careful to ignore and preserve mark bits,
+ − 293 including those in chain fields of markers. */
+ − 294
+ − 295 void
+ − 296 unchain_marker (Lisp_Object m)
+ − 297 {
440
+ − 298 Lisp_Marker *marker = XMARKER (m);
428
+ − 299 struct buffer *b = marker->buffer;
+ − 300
+ − 301 if (b == 0)
+ − 302 return;
+ − 303
+ − 304 #ifdef ERROR_CHECK_GC
+ − 305 assert (BUFFER_LIVE_P (b));
+ − 306 #endif
+ − 307
+ − 308 if (marker_next (marker))
+ − 309 marker_prev (marker_next (marker)) = marker_prev (marker);
+ − 310 if (marker_prev (marker))
+ − 311 marker_next (marker_prev (marker)) = marker_next (marker);
+ − 312 else
+ − 313 BUF_MARKERS (b) = marker_next (marker);
+ − 314
+ − 315 #ifdef ERROR_CHECK_GC
+ − 316 assert (marker != XMARKER (b->point_marker));
+ − 317 #endif
+ − 318
+ − 319 marker->buffer = 0;
+ − 320 }
+ − 321
665
+ − 322 Bytebpos
428
+ − 323 bi_marker_position (Lisp_Object marker)
+ − 324 {
440
+ − 325 Lisp_Marker *m = XMARKER (marker);
428
+ − 326 struct buffer *buf = m->buffer;
665
+ − 327 Bytebpos pos;
428
+ − 328
+ − 329 if (!buf)
563
+ − 330 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 331
+ − 332 /* FSF claims that marker indices could end up denormalized, i.e.
+ − 333 in the gap. This is way bogus if it ever happens, and means
+ − 334 something fucked up elsewhere. Since I've overhauled all this
+ − 335 shit, I don't think this can happen. In any case, the following
+ − 336 macro has an assert() in it that will catch these denormalized
+ − 337 positions. */
665
+ − 338 pos = membpos_to_bytebpos (buf, m->membpos);
428
+ − 339
665
+ − 340 #ifdef ERROR_CHECK_CHARBPOS
428
+ − 341 if (pos < BI_BUF_BEG (buf) || pos > BI_BUF_Z (buf))
+ − 342 abort ();
+ − 343 #endif
+ − 344
+ − 345 return pos;
+ − 346 }
+ − 347
665
+ − 348 Charbpos
428
+ − 349 marker_position (Lisp_Object marker)
+ − 350 {
+ − 351 struct buffer *buf = XMARKER (marker)->buffer;
+ − 352
+ − 353 if (!buf)
563
+ − 354 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 355
665
+ − 356 return bytebpos_to_charbpos (buf, bi_marker_position (marker));
428
+ − 357 }
+ − 358
+ − 359 void
665
+ − 360 set_bi_marker_position (Lisp_Object marker, Bytebpos pos)
428
+ − 361 {
440
+ − 362 Lisp_Marker *m = XMARKER (marker);
428
+ − 363 struct buffer *buf = m->buffer;
+ − 364
+ − 365 if (!buf)
563
+ − 366 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 367
665
+ − 368 #ifdef ERROR_CHECK_CHARBPOS
428
+ − 369 if (pos < BI_BUF_BEG (buf) || pos > BI_BUF_Z (buf))
+ − 370 abort ();
+ − 371 #endif
+ − 372
665
+ − 373 m->membpos = bytebpos_to_membpos (buf, pos);
428
+ − 374 }
+ − 375
+ − 376 void
665
+ − 377 set_marker_position (Lisp_Object marker, Charbpos pos)
428
+ − 378 {
+ − 379 struct buffer *buf = XMARKER (marker)->buffer;
+ − 380
+ − 381 if (!buf)
563
+ − 382 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 383
665
+ − 384 set_bi_marker_position (marker, charbpos_to_bytebpos (buf, pos));
428
+ − 385 }
+ − 386
+ − 387 static Lisp_Object
+ − 388 copy_marker_1 (Lisp_Object marker, Lisp_Object type, int noseeum)
+ − 389 {
+ − 390 REGISTER Lisp_Object new;
+ − 391
+ − 392 while (1)
+ − 393 {
+ − 394 if (INTP (marker) || MARKERP (marker))
+ − 395 {
+ − 396 if (noseeum)
+ − 397 new = noseeum_make_marker ();
+ − 398 else
+ − 399 new = Fmake_marker ();
+ − 400 Fset_marker (new, marker,
+ − 401 (MARKERP (marker) ? Fmarker_buffer (marker) : Qnil));
+ − 402 XMARKER (new)->insertion_type = !NILP (type);
+ − 403 return new;
+ − 404 }
+ − 405 else
+ − 406 marker = wrong_type_argument (Qinteger_or_marker_p, marker);
+ − 407 }
+ − 408
+ − 409 RETURN_NOT_REACHED (Qnil) /* not reached */
+ − 410 }
+ − 411
+ − 412 DEFUN ("copy-marker", Fcopy_marker, 1, 2, 0, /*
444
+ − 413 Return a new marker pointing at the same place as MARKER-OR-INTEGER.
+ − 414 If MARKER-OR-INTEGER is an integer, return a new marker pointing
428
+ − 415 at that position in the current buffer.
444
+ − 416 Optional argument MARKER-TYPE specifies the insertion type of the new
+ − 417 marker; see `marker-insertion-type'.
428
+ − 418 */
444
+ − 419 (marker_or_integer, marker_type))
428
+ − 420 {
444
+ − 421 return copy_marker_1 (marker_or_integer, marker_type, 0);
428
+ − 422 }
+ − 423
+ − 424 Lisp_Object
444
+ − 425 noseeum_copy_marker (Lisp_Object marker, Lisp_Object marker_type)
428
+ − 426 {
444
+ − 427 return copy_marker_1 (marker, marker_type, 1);
428
+ − 428 }
+ − 429
+ − 430 DEFUN ("marker-insertion-type", Fmarker_insertion_type, 1, 1, 0, /*
+ − 431 Return insertion type of MARKER: t if it stays after inserted text.
+ − 432 nil means the marker stays before text inserted there.
+ − 433 */
+ − 434 (marker))
+ − 435 {
+ − 436 CHECK_MARKER (marker);
+ − 437 return XMARKER (marker)->insertion_type ? Qt : Qnil;
+ − 438 }
+ − 439
+ − 440 DEFUN ("set-marker-insertion-type", Fset_marker_insertion_type, 2, 2, 0, /*
+ − 441 Set the insertion-type of MARKER to TYPE.
+ − 442 If TYPE is t, it means the marker advances when you insert text at it.
+ − 443 If TYPE is nil, it means the marker stays behind when you insert text at it.
+ − 444 */
+ − 445 (marker, type))
+ − 446 {
+ − 447 CHECK_MARKER (marker);
+ − 448
+ − 449 XMARKER (marker)->insertion_type = ! NILP (type);
+ − 450 return type;
+ − 451 }
+ − 452
+ − 453 /* #### What is the possible use of this? It looks quite useless to
+ − 454 me, because there is no way to find *which* markers are positioned
+ − 455 at POSITION. Additional bogosity bonus: (buffer-has-markers-at
+ − 456 (point)) will always return t because of the `point-marker'. The
+ − 457 same goes for the position of mark. Bletch!
+ − 458
+ − 459 Someone should discuss this with Stallman, but I don't have the
+ − 460 stomach. In fact, this function sucks so badly that I'm disabling
+ − 461 it by default (although I've debugged it). If you want to use it,
+ − 462 use extents instead. --hniksic */
+ − 463 #if 0
+ − 464 xxDEFUN ("buffer-has-markers-at", Fbuffer_has_markers_at, 1, 1, 0, /*
+ − 465 Return t if there are markers pointing at POSITION in the current buffer.
+ − 466 */
+ − 467 (position))
+ − 468 {
440
+ − 469 Lisp_Marker *marker;
665
+ − 470 Membpos pos;
428
+ − 471
665
+ − 472 /* A small optimization trick: convert POS to membpos now, rather
+ − 473 than converting every marker's memory index to charbpos. */
+ − 474 pos = bytebpos_to_membpos (current_buffer,
428
+ − 475 get_buffer_pos_byte (current_buffer, position,
+ − 476 GB_COERCE_RANGE));
+ − 477
+ − 478 for (marker = BUF_MARKERS (current_buffer);
+ − 479 marker;
+ − 480 marker = marker_next (marker))
+ − 481 {
665
+ − 482 /* We use marker->membpos, so we don't have to go through the
428
+ − 483 unwieldy operation of creating a Lisp_Object for
+ − 484 marker_position() every time around. */
665
+ − 485 if (marker->membpos == pos)
428
+ − 486 return Qt;
+ − 487 }
+ − 488
+ − 489 return Qnil;
+ − 490 }
+ − 491 #endif /* 0 */
+ − 492
+ − 493 #ifdef MEMORY_USAGE_STATS
+ − 494
+ − 495 int
+ − 496 compute_buffer_marker_usage (struct buffer *b, struct overhead_stats *ovstats)
+ − 497 {
440
+ − 498 Lisp_Marker *m;
428
+ − 499 int total = 0;
+ − 500 int overhead;
+ − 501
+ − 502 for (m = BUF_MARKERS (b); m; m = m->next)
440
+ − 503 total += sizeof (Lisp_Marker);
428
+ − 504 ovstats->was_requested += total;
+ − 505 overhead = fixed_type_block_overhead (total);
+ − 506 /* #### claiming this is all malloc overhead is not really right,
+ − 507 but it has to go somewhere. */
+ − 508 ovstats->malloc_overhead += overhead;
+ − 509 return total + overhead;
+ − 510 }
+ − 511
+ − 512 #endif /* MEMORY_USAGE_STATS */
+ − 513
+ − 514
+ − 515 void
+ − 516 syms_of_marker (void)
+ − 517 {
442
+ − 518 INIT_LRECORD_IMPLEMENTATION (marker);
+ − 519
428
+ − 520 DEFSUBR (Fmarker_position);
+ − 521 DEFSUBR (Fmarker_buffer);
+ − 522 DEFSUBR (Fset_marker);
+ − 523 DEFSUBR (Fcopy_marker);
+ − 524 DEFSUBR (Fmarker_insertion_type);
+ − 525 DEFSUBR (Fset_marker_insertion_type);
+ − 526 #if 0 /* FSFmacs crock */
+ − 527 DEFSUBR (Fbuffer_has_markers_at);
+ − 528 #endif
+ − 529 }
+ − 530
+ − 531 void
+ − 532 init_buffer_markers (struct buffer *b)
+ − 533 {
+ − 534 Lisp_Object buf;
+ − 535
+ − 536 XSETBUFFER (buf, b);
+ − 537 b->mark = Fmake_marker ();
+ − 538 BUF_MARKERS (b) = 0;
+ − 539 b->point_marker = Fmake_marker ();
+ − 540 Fset_marker (b->point_marker,
+ − 541 /* For indirect buffers, point is already set. */
+ − 542 b->base_buffer ? make_int (BUF_PT (b)) : make_int (1),
+ − 543 buf);
+ − 544 }
+ − 545
+ − 546 void
+ − 547 uninit_buffer_markers (struct buffer *b)
+ − 548 {
+ − 549 /* Unchain all markers of this buffer
+ − 550 and leave them pointing nowhere. */
440
+ − 551 REGISTER Lisp_Marker *m, *next;
428
+ − 552 for (m = BUF_MARKERS (b); m; m = next)
+ − 553 {
+ − 554 m->buffer = 0;
+ − 555 next = marker_next (m);
+ − 556 marker_next (m) = 0;
+ − 557 marker_prev (m) = 0;
+ − 558 }
+ − 559 BUF_MARKERS (b) = 0;
+ − 560 }
