428
+ − 1 /* Markers: examining, setting and killing.
+ − 2 Copyright (C) 1985, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
800
+ − 3 Copyright (C) 2002 Ben Wing.
428
+ − 4
+ − 5 This file is part of XEmacs.
+ − 6
+ − 7 XEmacs is free software; you can redistribute it and/or modify it
+ − 8 under the terms of the GNU General Public License as published by the
+ − 9 Free Software Foundation; either version 2, or (at your option) any
+ − 10 later version.
+ − 11
+ − 12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
+ − 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ − 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ − 15 for more details.
+ − 16
+ − 17 You should have received a copy of the GNU General Public License
+ − 18 along with XEmacs; see the file COPYING. If not, write to
+ − 19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ − 20 Boston, MA 02111-1307, USA. */
+ − 21
+ − 22 /* Synched up with: FSF 19.30. */
+ − 23
+ − 24 /* This file has been Mule-ized. */
+ − 25
+ − 26 /* Note that markers are currently kept in an unordered list.
+ − 27 This means that marker operations may be inefficient if
+ − 28 there are a bunch of markers in the buffer. This probably
+ − 29 won't have a significant impact on redisplay (which uses
+ − 30 markers), but if it does, it wouldn't be too hard to change
+ − 31 to an ordered gap array. (Just copy the code from extents.c.)
+ − 32 */
+ − 33
+ − 34 #include <config.h>
+ − 35 #include "lisp.h"
+ − 36
+ − 37 #include "buffer.h"
+ − 38
+ − 39 static Lisp_Object
+ − 40 mark_marker (Lisp_Object obj)
+ − 41 {
440
+ − 42 Lisp_Marker *marker = XMARKER (obj);
428
+ − 43 Lisp_Object buf;
+ − 44 /* DO NOT mark through the marker's chain.
+ − 45 The buffer's markers chain does not preserve markers from gc;
+ − 46 Instead, markers are removed from the chain when they are freed
+ − 47 by gc.
+ − 48 */
+ − 49 if (!marker->buffer)
+ − 50 return (Qnil);
+ − 51
793
+ − 52 buf = wrap_buffer (marker->buffer);
428
+ − 53 return (buf);
+ − 54 }
+ − 55
+ − 56 static void
2286
+ − 57 print_marker (Lisp_Object obj, Lisp_Object printcharfun,
+ − 58 int UNUSED (escapeflag))
428
+ − 59 {
440
+ − 60 Lisp_Marker *marker = XMARKER (obj);
428
+ − 61
+ − 62 if (print_readably)
563
+ − 63 printing_unreadable_object ("#<marker 0x%lx>", (long) marker);
428
+ − 64
826
+ − 65 write_c_string (printcharfun, GETTEXT ("#<marker "));
428
+ − 66 if (!marker->buffer)
826
+ − 67 write_c_string (printcharfun, GETTEXT ("in no buffer"));
428
+ − 68 else
+ − 69 {
826
+ − 70 write_fmt_string (printcharfun, "at %ld in ",
+ − 71 (long) marker_position (obj));
428
+ − 72 print_internal (marker->buffer->name, printcharfun, 0);
+ − 73 }
826
+ − 74 if (marker->insertion_type)
+ − 75 write_c_string (printcharfun, " insertion-type=t");
800
+ − 76 write_fmt_string (printcharfun, " 0x%lx>", (long) marker);
428
+ − 77 }
+ − 78
+ − 79 static int
2286
+ − 80 marker_equal (Lisp_Object obj1, Lisp_Object obj2, int UNUSED (depth))
428
+ − 81 {
440
+ − 82 Lisp_Marker *marker1 = XMARKER (obj1);
+ − 83 Lisp_Marker *marker2 = XMARKER (obj2);
428
+ − 84
+ − 85 return ((marker1->buffer == marker2->buffer) &&
665
+ − 86 (marker1->membpos == marker2->membpos ||
428
+ − 87 /* All markers pointing nowhere are equal */
+ − 88 !marker1->buffer));
+ − 89 }
+ − 90
2515
+ − 91 static Hashcode
2286
+ − 92 marker_hash (Lisp_Object obj, int UNUSED (depth))
428
+ − 93 {
2515
+ − 94 Hashcode hash = (Hashcode) XMARKER (obj)->buffer;
428
+ − 95 if (hash)
665
+ − 96 hash = HASH2 (hash, XMARKER (obj)->membpos);
428
+ − 97 return hash;
+ − 98 }
+ − 99
1204
+ − 100 static const struct memory_description marker_description[] = {
2551
+ − 101 { XD_LISP_OBJECT, offsetof (Lisp_Marker, next), 0, { 0 }, XD_FLAG_NO_KKCC },
+ − 102 { XD_LISP_OBJECT, offsetof (Lisp_Marker, prev), 0, { 0 }, XD_FLAG_NO_KKCC },
440
+ − 103 { XD_LISP_OBJECT, offsetof (Lisp_Marker, buffer) },
428
+ − 104 { XD_END }
+ − 105 };
+ − 106
934
+ − 107 DEFINE_BASIC_LRECORD_IMPLEMENTATION ("marker", marker,
+ − 108 1, /*dumpable-flag*/
+ − 109 mark_marker, print_marker, 0,
1204
+ − 110 marker_equal, marker_hash,
+ − 111 marker_description, Lisp_Marker);
428
+ − 112
+ − 113 /* Operations on markers. */
+ − 114
+ − 115 DEFUN ("marker-buffer", Fmarker_buffer, 1, 1, 0, /*
+ − 116 Return the buffer that MARKER points into, or nil if none.
+ − 117 Return nil if MARKER points into a dead buffer or doesn't point anywhere.
+ − 118 */
+ − 119 (marker))
+ − 120 {
+ − 121 struct buffer *buf;
+ − 122 CHECK_MARKER (marker);
+ − 123 /* Return marker's buffer only if it is not dead. */
+ − 124 if ((buf = XMARKER (marker)->buffer) && BUFFER_LIVE_P (buf))
+ − 125 {
793
+ − 126 return wrap_buffer (buf);
428
+ − 127 }
+ − 128 return Qnil;
+ − 129 }
+ − 130
+ − 131 DEFUN ("marker-position", Fmarker_position, 1, 1, 0, /*
+ − 132 Return the position MARKER points at, as a character number.
+ − 133 Return `nil' if marker doesn't point anywhere.
+ − 134 */
+ − 135 (marker))
+ − 136 {
+ − 137 CHECK_MARKER (marker);
+ − 138 return XMARKER (marker)->buffer ? make_int (marker_position (marker)) : Qnil;
+ − 139 }
+ − 140
+ − 141 #if 0 /* useful debugging function */
+ − 142
+ − 143 static void
+ − 144 check_marker_circularities (struct buffer *buf)
+ − 145 {
440
+ − 146 Lisp_Marker *tortoise, *hare;
428
+ − 147
+ − 148 tortoise = BUF_MARKERS (buf);
+ − 149 hare = tortoise;
+ − 150
+ − 151 if (!tortoise)
+ − 152 return;
+ − 153
+ − 154 while (1)
+ − 155 {
+ − 156 assert (hare->buffer == buf);
+ − 157 hare = hare->next;
+ − 158 if (!hare)
+ − 159 return;
+ − 160 assert (hare->buffer == buf);
+ − 161 hare = hare->next;
+ − 162 if (!hare)
+ − 163 return;
+ − 164 tortoise = tortoise->next;
+ − 165 assert (tortoise != hare);
+ − 166 }
+ − 167 }
+ − 168
+ − 169 #endif
+ − 170
+ − 171 static Lisp_Object
444
+ − 172 set_marker_internal (Lisp_Object marker, Lisp_Object position,
+ − 173 Lisp_Object buffer, int restricted_p)
428
+ − 174 {
665
+ − 175 Charbpos charno;
428
+ − 176 struct buffer *b;
440
+ − 177 Lisp_Marker *m;
428
+ − 178 int point_p;
+ − 179
+ − 180 CHECK_MARKER (marker);
+ − 181
+ − 182 point_p = POINT_MARKER_P (marker);
+ − 183
+ − 184 /* If position is nil or a marker that points nowhere,
+ − 185 make this marker point nowhere. */
444
+ − 186 if (NILP (position) ||
+ − 187 (MARKERP (position) && !XMARKER (position)->buffer))
428
+ − 188 {
+ − 189 if (point_p)
563
+ − 190 invalid_operation ("Can't make point-marker point nowhere",
+ − 191 marker);
428
+ − 192 if (XMARKER (marker)->buffer)
+ − 193 unchain_marker (marker);
+ − 194 return marker;
+ − 195 }
+ − 196
444
+ − 197 CHECK_INT_COERCE_MARKER (position);
428
+ − 198 if (NILP (buffer))
+ − 199 b = current_buffer;
+ − 200 else
+ − 201 {
+ − 202 CHECK_BUFFER (buffer);
+ − 203 b = XBUFFER (buffer);
+ − 204 /* If buffer is dead, set marker to point nowhere. */
+ − 205 if (!BUFFER_LIVE_P (XBUFFER (buffer)))
+ − 206 {
+ − 207 if (point_p)
563
+ − 208 invalid_operation
428
+ − 209 ("Can't move point-marker in a killed buffer", marker);
+ − 210 if (XMARKER (marker)->buffer)
+ − 211 unchain_marker (marker);
+ − 212 return marker;
+ − 213 }
+ − 214 }
+ − 215
444
+ − 216 charno = XINT (position);
428
+ − 217 m = XMARKER (marker);
+ − 218
+ − 219 if (restricted_p)
+ − 220 {
+ − 221 if (charno < BUF_BEGV (b)) charno = BUF_BEGV (b);
+ − 222 if (charno > BUF_ZV (b)) charno = BUF_ZV (b);
+ − 223 }
+ − 224 else
+ − 225 {
+ − 226 if (charno < BUF_BEG (b)) charno = BUF_BEG (b);
+ − 227 if (charno > BUF_Z (b)) charno = BUF_Z (b);
+ − 228 }
+ − 229
+ − 230 if (point_p)
+ − 231 {
+ − 232 #ifndef moving_point_by_moving_its_marker_is_a_bug
+ − 233 BUF_SET_PT (b, charno); /* this will move the marker */
+ − 234 #else /* It's not a feature, so it must be a bug */
563
+ − 235 invalid_operation ("DEBUG: attempt to move point via point-marker",
+ − 236 marker);
428
+ − 237 #endif
+ − 238 }
+ − 239 else
+ − 240 {
665
+ − 241 m->membpos = charbpos_to_membpos (b, charno);
428
+ − 242 }
+ − 243
+ − 244 if (m->buffer != b)
+ − 245 {
+ − 246 if (point_p)
563
+ − 247 invalid_operation ("Can't change buffer of point-marker", marker);
428
+ − 248 if (m->buffer != 0)
+ − 249 unchain_marker (marker);
+ − 250 m->buffer = b;
+ − 251 marker_next (m) = BUF_MARKERS (b);
+ − 252 marker_prev (m) = 0;
+ − 253 if (BUF_MARKERS (b))
+ − 254 marker_prev (BUF_MARKERS (b)) = m;
+ − 255 BUF_MARKERS (b) = m;
+ − 256 }
+ − 257
+ − 258 return marker;
+ − 259 }
+ − 260
+ − 261
+ − 262 DEFUN ("set-marker", Fset_marker, 2, 3, 0, /*
444
+ − 263 Move MARKER to position POSITION in BUFFER.
+ − 264 POSITION can be a marker, an integer or nil. If POSITION is an
+ − 265 integer, make MARKER point before the POSITIONth character in BUFFER.
+ − 266 If POSITION is nil, makes MARKER point nowhere. Then it no longer
+ − 267 slows down editing in any buffer. If POSITION is less than 1, move
+ − 268 MARKER to the beginning of BUFFER. If POSITION is greater than the
+ − 269 size of BUFFER, move MARKER to the end of BUFFER.
428
+ − 270 BUFFER defaults to the current buffer.
444
+ − 271 If this marker was returned by (point-marker t), then changing its
+ − 272 position moves point. You cannot change its buffer or make it point
+ − 273 nowhere.
+ − 274 The return value is MARKER.
428
+ − 275 */
444
+ − 276 (marker, position, buffer))
428
+ − 277 {
444
+ − 278 return set_marker_internal (marker, position, buffer, 0);
428
+ − 279 }
+ − 280
+ − 281
+ − 282 /* This version of Fset_marker won't let the position
+ − 283 be outside the visible part. */
+ − 284 Lisp_Object
444
+ − 285 set_marker_restricted (Lisp_Object marker, Lisp_Object position,
+ − 286 Lisp_Object buffer)
428
+ − 287 {
444
+ − 288 return set_marker_internal (marker, position, buffer, 1);
428
+ − 289 }
+ − 290
+ − 291
+ − 292 /* This is called during garbage collection,
+ − 293 so we must be careful to ignore and preserve mark bits,
+ − 294 including those in chain fields of markers. */
+ − 295
+ − 296 void
+ − 297 unchain_marker (Lisp_Object m)
+ − 298 {
440
+ − 299 Lisp_Marker *marker = XMARKER (m);
428
+ − 300 struct buffer *b = marker->buffer;
+ − 301
+ − 302 if (b == 0)
+ − 303 return;
+ − 304
800
+ − 305 #ifdef ERROR_CHECK_STRUCTURES
428
+ − 306 assert (BUFFER_LIVE_P (b));
+ − 307 #endif
+ − 308
+ − 309 if (marker_next (marker))
+ − 310 marker_prev (marker_next (marker)) = marker_prev (marker);
+ − 311 if (marker_prev (marker))
+ − 312 marker_next (marker_prev (marker)) = marker_next (marker);
+ − 313 else
+ − 314 BUF_MARKERS (b) = marker_next (marker);
+ − 315
800
+ − 316 #ifdef ERROR_CHECK_STRUCTURES
428
+ − 317 assert (marker != XMARKER (b->point_marker));
+ − 318 #endif
+ − 319
+ − 320 marker->buffer = 0;
+ − 321 }
+ − 322
665
+ − 323 Bytebpos
826
+ − 324 byte_marker_position (Lisp_Object marker)
428
+ − 325 {
440
+ − 326 Lisp_Marker *m = XMARKER (marker);
428
+ − 327 struct buffer *buf = m->buffer;
665
+ − 328 Bytebpos pos;
428
+ − 329
+ − 330 if (!buf)
563
+ − 331 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 332
+ − 333 /* FSF claims that marker indices could end up denormalized, i.e.
+ − 334 in the gap. This is way bogus if it ever happens, and means
+ − 335 something fucked up elsewhere. Since I've overhauled all this
+ − 336 shit, I don't think this can happen. In any case, the following
+ − 337 macro has an assert() in it that will catch these denormalized
+ − 338 positions. */
665
+ − 339 pos = membpos_to_bytebpos (buf, m->membpos);
428
+ − 340
+ − 341 return pos;
+ − 342 }
+ − 343
665
+ − 344 Charbpos
428
+ − 345 marker_position (Lisp_Object marker)
+ − 346 {
+ − 347 struct buffer *buf = XMARKER (marker)->buffer;
+ − 348
+ − 349 if (!buf)
563
+ − 350 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 351
826
+ − 352 return bytebpos_to_charbpos (buf, byte_marker_position (marker));
428
+ − 353 }
+ − 354
+ − 355 void
826
+ − 356 set_byte_marker_position (Lisp_Object marker, Bytebpos pos)
428
+ − 357 {
440
+ − 358 Lisp_Marker *m = XMARKER (marker);
428
+ − 359 struct buffer *buf = m->buffer;
+ − 360
+ − 361 if (!buf)
563
+ − 362 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 363
665
+ − 364 m->membpos = bytebpos_to_membpos (buf, pos);
428
+ − 365 }
+ − 366
+ − 367 void
665
+ − 368 set_marker_position (Lisp_Object marker, Charbpos pos)
428
+ − 369 {
+ − 370 struct buffer *buf = XMARKER (marker)->buffer;
+ − 371
+ − 372 if (!buf)
563
+ − 373 invalid_argument ("Marker does not point anywhere", Qunbound);
428
+ − 374
826
+ − 375 set_byte_marker_position (marker, charbpos_to_bytebpos (buf, pos));
428
+ − 376 }
+ − 377
+ − 378 static Lisp_Object
+ − 379 copy_marker_1 (Lisp_Object marker, Lisp_Object type, int noseeum)
+ − 380 {
+ − 381 REGISTER Lisp_Object new;
+ − 382
+ − 383 while (1)
+ − 384 {
+ − 385 if (INTP (marker) || MARKERP (marker))
+ − 386 {
+ − 387 if (noseeum)
+ − 388 new = noseeum_make_marker ();
+ − 389 else
+ − 390 new = Fmake_marker ();
+ − 391 Fset_marker (new, marker,
+ − 392 (MARKERP (marker) ? Fmarker_buffer (marker) : Qnil));
+ − 393 XMARKER (new)->insertion_type = !NILP (type);
+ − 394 return new;
+ − 395 }
+ − 396 else
+ − 397 marker = wrong_type_argument (Qinteger_or_marker_p, marker);
+ − 398 }
+ − 399
1204
+ − 400 RETURN_NOT_REACHED (Qnil); /* not reached */
428
+ − 401 }
+ − 402
+ − 403 DEFUN ("copy-marker", Fcopy_marker, 1, 2, 0, /*
444
+ − 404 Return a new marker pointing at the same place as MARKER-OR-INTEGER.
+ − 405 If MARKER-OR-INTEGER is an integer, return a new marker pointing
428
+ − 406 at that position in the current buffer.
444
+ − 407 Optional argument MARKER-TYPE specifies the insertion type of the new
+ − 408 marker; see `marker-insertion-type'.
428
+ − 409 */
444
+ − 410 (marker_or_integer, marker_type))
428
+ − 411 {
444
+ − 412 return copy_marker_1 (marker_or_integer, marker_type, 0);
428
+ − 413 }
+ − 414
+ − 415 Lisp_Object
444
+ − 416 noseeum_copy_marker (Lisp_Object marker, Lisp_Object marker_type)
428
+ − 417 {
444
+ − 418 return copy_marker_1 (marker, marker_type, 1);
428
+ − 419 }
+ − 420
+ − 421 DEFUN ("marker-insertion-type", Fmarker_insertion_type, 1, 1, 0, /*
+ − 422 Return insertion type of MARKER: t if it stays after inserted text.
+ − 423 nil means the marker stays before text inserted there.
+ − 424 */
+ − 425 (marker))
+ − 426 {
+ − 427 CHECK_MARKER (marker);
+ − 428 return XMARKER (marker)->insertion_type ? Qt : Qnil;
+ − 429 }
+ − 430
+ − 431 DEFUN ("set-marker-insertion-type", Fset_marker_insertion_type, 2, 2, 0, /*
+ − 432 Set the insertion-type of MARKER to TYPE.
+ − 433 If TYPE is t, it means the marker advances when you insert text at it.
+ − 434 If TYPE is nil, it means the marker stays behind when you insert text at it.
+ − 435 */
+ − 436 (marker, type))
+ − 437 {
+ − 438 CHECK_MARKER (marker);
+ − 439
+ − 440 XMARKER (marker)->insertion_type = ! NILP (type);
+ − 441 return type;
+ − 442 }
+ − 443
+ − 444 /* #### What is the possible use of this? It looks quite useless to
+ − 445 me, because there is no way to find *which* markers are positioned
+ − 446 at POSITION. Additional bogosity bonus: (buffer-has-markers-at
+ − 447 (point)) will always return t because of the `point-marker'. The
+ − 448 same goes for the position of mark. Bletch!
+ − 449
+ − 450 Someone should discuss this with Stallman, but I don't have the
+ − 451 stomach. In fact, this function sucks so badly that I'm disabling
+ − 452 it by default (although I've debugged it). If you want to use it,
+ − 453 use extents instead. --hniksic */
+ − 454 #if 0
826
+ − 455 DEFUN ("buffer-has-markers-at", Fbuffer_has_markers_at, 1, 1, 0, /*
428
+ − 456 Return t if there are markers pointing at POSITION in the current buffer.
+ − 457 */
+ − 458 (position))
+ − 459 {
440
+ − 460 Lisp_Marker *marker;
665
+ − 461 Membpos pos;
428
+ − 462
665
+ − 463 /* A small optimization trick: convert POS to membpos now, rather
+ − 464 than converting every marker's memory index to charbpos. */
+ − 465 pos = bytebpos_to_membpos (current_buffer,
428
+ − 466 get_buffer_pos_byte (current_buffer, position,
+ − 467 GB_COERCE_RANGE));
+ − 468
+ − 469 for (marker = BUF_MARKERS (current_buffer);
+ − 470 marker;
+ − 471 marker = marker_next (marker))
+ − 472 {
665
+ − 473 /* We use marker->membpos, so we don't have to go through the
428
+ − 474 unwieldy operation of creating a Lisp_Object for
+ − 475 marker_position() every time around. */
665
+ − 476 if (marker->membpos == pos)
428
+ − 477 return Qt;
+ − 478 }
+ − 479
+ − 480 return Qnil;
+ − 481 }
+ − 482 #endif /* 0 */
+ − 483
+ − 484 #ifdef MEMORY_USAGE_STATS
+ − 485
+ − 486 int
+ − 487 compute_buffer_marker_usage (struct buffer *b, struct overhead_stats *ovstats)
+ − 488 {
440
+ − 489 Lisp_Marker *m;
428
+ − 490 int total = 0;
+ − 491 int overhead;
+ − 492
+ − 493 for (m = BUF_MARKERS (b); m; m = m->next)
440
+ − 494 total += sizeof (Lisp_Marker);
428
+ − 495 ovstats->was_requested += total;
+ − 496 overhead = fixed_type_block_overhead (total);
+ − 497 /* #### claiming this is all malloc overhead is not really right,
+ − 498 but it has to go somewhere. */
+ − 499 ovstats->malloc_overhead += overhead;
+ − 500 return total + overhead;
+ − 501 }
+ − 502
+ − 503 #endif /* MEMORY_USAGE_STATS */
+ − 504
+ − 505
+ − 506 void
+ − 507 syms_of_marker (void)
+ − 508 {
442
+ − 509 INIT_LRECORD_IMPLEMENTATION (marker);
+ − 510
428
+ − 511 DEFSUBR (Fmarker_position);
+ − 512 DEFSUBR (Fmarker_buffer);
+ − 513 DEFSUBR (Fset_marker);
+ − 514 DEFSUBR (Fcopy_marker);
+ − 515 DEFSUBR (Fmarker_insertion_type);
+ − 516 DEFSUBR (Fset_marker_insertion_type);
+ − 517 #if 0 /* FSFmacs crock */
+ − 518 DEFSUBR (Fbuffer_has_markers_at);
+ − 519 #endif
+ − 520 }
+ − 521
+ − 522 void
+ − 523 init_buffer_markers (struct buffer *b)
+ − 524 {
793
+ − 525 Lisp_Object buf = wrap_buffer (b);
428
+ − 526
+ − 527 b->mark = Fmake_marker ();
+ − 528 BUF_MARKERS (b) = 0;
+ − 529 b->point_marker = Fmake_marker ();
+ − 530 Fset_marker (b->point_marker,
+ − 531 /* For indirect buffers, point is already set. */
+ − 532 b->base_buffer ? make_int (BUF_PT (b)) : make_int (1),
+ − 533 buf);
+ − 534 }
+ − 535
+ − 536 void
+ − 537 uninit_buffer_markers (struct buffer *b)
+ − 538 {
+ − 539 /* Unchain all markers of this buffer
+ − 540 and leave them pointing nowhere. */
440
+ − 541 REGISTER Lisp_Marker *m, *next;
428
+ − 542 for (m = BUF_MARKERS (b); m; m = next)
+ − 543 {
+ − 544 m->buffer = 0;
+ − 545 next = marker_next (m);
+ − 546 marker_next (m) = 0;
+ − 547 marker_prev (m) = 0;
+ − 548 }
+ − 549 BUF_MARKERS (b) = 0;
+ − 550 }