buffer.c 198 KB
Newer Older
Roland McGrath's avatar
Roland McGrath committed
1
/* Buffer manipulation primitives for GNU Emacs.
2

3
Copyright (C) 1985-1989, 1993-1995, 1997-2011  Free Software Foundation, Inc.
Roland McGrath's avatar
Roland McGrath committed
4 5 6

This file is part of GNU Emacs.

7
GNU Emacs is free software: you can redistribute it and/or modify
Roland McGrath's avatar
Roland McGrath committed
8
it under the terms of the GNU General Public License as published by
9 10
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Roland McGrath's avatar
Roland McGrath committed
11 12 13 14 15 16 17

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
18
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
Roland McGrath's avatar
Roland McGrath committed
19

20
#include <config.h>
Roland McGrath's avatar
Roland McGrath committed
21

22 23
#include <sys/types.h>
#include <sys/stat.h>
Roland McGrath's avatar
Roland McGrath committed
24
#include <sys/param.h>
Richard M. Stallman's avatar
Richard M. Stallman committed
25
#include <errno.h>
Dave Love's avatar
Dave Love committed
26
#include <stdio.h>
27
#include <setjmp.h>
Andreas Schwab's avatar
Andreas Schwab committed
28
#include <unistd.h>
29

Paul Eggert's avatar
Paul Eggert committed
30 31
#include <verify.h>

Roland McGrath's avatar
Roland McGrath committed
32
#include "lisp.h"
33
#include "intervals.h"
Roland McGrath's avatar
Roland McGrath committed
34 35 36
#include "window.h"
#include "commands.h"
#include "buffer.h"
37
#include "character.h"
38
#include "region-cache.h"
Roland McGrath's avatar
Roland McGrath committed
39
#include "indent.h"
Richard M. Stallman's avatar
Richard M. Stallman committed
40
#include "blockinput.h"
41
#include "keyboard.h"
Stefan Monnier's avatar
Stefan Monnier committed
42
#include "keymap.h"
43
#include "frame.h"
Roland McGrath's avatar
Roland McGrath committed
44 45 46 47

struct buffer *current_buffer;		/* the current buffer */

/* First buffer in chain of all buffers (in reverse order of creation).
48
   Threaded through ->header.next.buffer.  */
Roland McGrath's avatar
Roland McGrath committed
49 50 51 52 53 54 55 56 57 58

struct buffer *all_buffers;

/* This structure holds the default values of the buffer-local variables
   defined with DEFVAR_PER_BUFFER, that have special slots in each buffer.
   The default value occupies the same slot in this structure
   as an individual buffer's value occupies in that buffer.
   Setting the default value also goes through the alist of buffers
   and stores into each buffer that does not say it has a local value.  */

Kenichi Handa's avatar
Kenichi Handa committed
59
DECL_ALIGN (struct buffer, buffer_defaults);
Roland McGrath's avatar
Roland McGrath committed
60 61 62 63 64 65 66 67 68 69 70

/* A Lisp_Object pointer to the above, used for staticpro */

static Lisp_Object Vbuffer_defaults;

/* This structure marks which slots in a buffer have corresponding
   default values in buffer_defaults.
   Each such slot has a nonzero value in this structure.
   The value has only one nonzero bit.

   When a buffer has its own local value for a slot,
71 72
   the entry for that slot (found in the same slot in this structure)
   is turned on in the buffer's local_flags array.
Roland McGrath's avatar
Roland McGrath committed
73 74 75 76 77 78 79 80 81 82 83 84 85

   If a slot in this structure is -1, then even though there may
   be a DEFVAR_PER_BUFFER for the slot, there is no default value for it;
   and the corresponding slot in buffer_defaults is not used.

   If a slot in this structure corresponding to a DEFVAR_PER_BUFFER is
   zero, that is a bug */

struct buffer buffer_local_flags;

/* This structure holds the names of symbols whose values may be
   buffer-local.  It is indexed and accessed in the same way as the above. */

Kenichi Handa's avatar
Kenichi Handa committed
86 87
DECL_ALIGN (struct buffer, buffer_local_symbols);

Roland McGrath's avatar
Roland McGrath committed
88 89 90
/* A Lisp_Object pointer to the above, used for staticpro */
static Lisp_Object Vbuffer_local_symbols;

91 92 93 94 95 96
/* Return the symbol of the per-buffer variable at offset OFFSET in
   the buffer structure.  */

#define PER_BUFFER_SYMBOL(OFFSET) \
      (*(Lisp_Object *)((OFFSET) + (char *) &buffer_local_symbols))

97 98
/* Flags indicating which built-in buffer-local variables
   are permanent locals.  */
99
static char buffer_permanent_local_flags[MAX_PER_BUFFER_VARS];
100 101 102

/* Number of per-buffer variables used.  */

103
int last_per_buffer_idx;
104

105 106
static Lisp_Object Fset_buffer_major_mode (Lisp_Object);
static Lisp_Object Fdelete_overlay (Lisp_Object);
107 108 109 110 111
static void call_overlay_mod_hooks (Lisp_Object list, Lisp_Object overlay,
                                    int after, Lisp_Object arg1,
                                    Lisp_Object arg2, Lisp_Object arg3);
static void swap_out_buffer_local_variables (struct buffer *b);
static void reset_buffer_local_variables (struct buffer *b, int permanent_too);
Roland McGrath's avatar
Roland McGrath committed
112 113 114 115 116 117

/* Alist of all buffer names vs the buffers. */
/* This used to be a variable, but is no longer,
 to prevent lossage due to user rplac'ing this alist or its elements.  */
Lisp_Object Vbuffer_alist;

118
static Lisp_Object Qkill_buffer_query_functions;
119

120
/* Hook run before changing a major mode.  */
121
static Lisp_Object Qchange_major_mode_hook;
122

Jim Blandy's avatar
Jim Blandy committed
123
Lisp_Object Qfirst_change_hook;
124 125
Lisp_Object Qbefore_change_functions;
Lisp_Object Qafter_change_functions;
126
static Lisp_Object Qucs_set_table_for_input;
Roland McGrath's avatar
Roland McGrath committed
127

128 129
static Lisp_Object Qfundamental_mode, Qmode_class, Qpermanent_local;
static Lisp_Object Qpermanent_local_hook;
Roland McGrath's avatar
Roland McGrath committed
130

131
static Lisp_Object Qprotected_field;
Roland McGrath's avatar
Roland McGrath committed
132

133
static Lisp_Object QSFundamental;	/* A string "Fundamental" */
Roland McGrath's avatar
Roland McGrath committed
134

135
static Lisp_Object Qkill_buffer_hook;
136
static Lisp_Object Qbuffer_list_update_hook;
Roland McGrath's avatar
Roland McGrath committed
137

138
static Lisp_Object Qget_file_buffer;
Richard M. Stallman's avatar
Richard M. Stallman committed
139

140
static Lisp_Object Qoverlayp;
Jim Blandy's avatar
Jim Blandy committed
141

142
Lisp_Object Qpriority, Qbefore_string, Qafter_string;
143

144
static Lisp_Object Qevaporate;
145

146 147 148 149
Lisp_Object Qmodification_hooks;
Lisp_Object Qinsert_in_front_hooks;
Lisp_Object Qinsert_behind_hooks;

150 151 152 153 154
static void alloc_buffer_text (struct buffer *, size_t);
static void free_buffer_text (struct buffer *b);
static struct Lisp_Overlay * copy_overlays (struct buffer *, struct Lisp_Overlay *);
static void modify_overlay (struct buffer *, EMACS_INT, EMACS_INT);
static Lisp_Object buffer_lisp_local_variables (struct buffer *);
155

Roland McGrath's avatar
Roland McGrath committed
156 157 158
/* For debugging; temporary.  See set_buffer_internal.  */
/* Lisp_Object Qlisp_mode, Vcheck_symbol; */

159
void
160
nsberror (Lisp_Object spec)
Roland McGrath's avatar
Roland McGrath committed
161
{
162
  if (STRINGP (spec))
163
    error ("No buffer named %s", SDATA (spec));
Roland McGrath's avatar
Roland McGrath committed
164 165 166
  error ("Invalid buffer argument");
}

Paul Eggert's avatar
Paul Eggert committed
167
DEFUN ("buffer-live-p", Fbuffer_live_p, Sbuffer_live_p, 1, 1, 0,
168 169
       doc: /* Return non-nil if OBJECT is a buffer which has not been killed.
Value is nil if OBJECT is not a buffer or if it has been killed.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
170
  (Lisp_Object object)
171
{
Tom Tromey's avatar
Tom Tromey committed
172
  return ((BUFFERP (object) && ! NILP (BVAR (XBUFFER (object), name)))
173 174 175
	  ? Qt : Qnil);
}

176
DEFUN ("buffer-list", Fbuffer_list, Sbuffer_list, 0, 1, 0,
177
       doc: /* Return a list of all existing live buffers.
178 179 180
If the optional arg FRAME is a frame, we return the buffer list in the
proper order for that frame: the buffers show in FRAME come first,
followed by the rest of the buffers.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
181
  (Lisp_Object frame)
Roland McGrath's avatar
Roland McGrath committed
182
{
183
  Lisp_Object general;
184 185 186 187
  general = Fmapcar (Qcdr, Vbuffer_alist);

  if (FRAMEP (frame))
    {
188 189
      Lisp_Object framelist, prevlist, tail;
      Lisp_Object args[3];
190

191
      CHECK_FRAME (frame);
192
      framelist = Fcopy_sequence (XFRAME (frame)->buffer_list);
193 194
      prevlist = Fnreverse (Fcopy_sequence
			    (XFRAME (frame)->buried_buffer_list));
195

196 197
      /* Remove from GENERAL any buffer that duplicates one in
         FRAMELIST or PREVLIST.  */
198
      tail = framelist;
199
      while (CONSP (tail))
200
	{
201 202
	  general = Fdelq (XCAR (tail), general);
	  tail = XCDR (tail);
203
	}
204 205 206 207 208 209 210 211 212 213 214
      tail = prevlist;
      while (CONSP (tail))
	{
	  general = Fdelq (XCAR (tail), general);
	  tail = XCDR (tail);
	}

      args[0] = framelist;
      args[1] = general;
      args[2] = prevlist;
      return Fnconc (3, args);
215
    }
216 217
  else
    return general;
Roland McGrath's avatar
Roland McGrath committed
218 219
}

220 221 222 223 224
/* Like Fassoc, but use Fstring_equal to compare
   (which ignores text properties),
   and don't ever QUIT.  */

static Lisp_Object
225
assoc_ignore_text_properties (register Lisp_Object key, Lisp_Object list)
226 227
{
  register Lisp_Object tail;
228
  for (tail = list; CONSP (tail); tail = XCDR (tail))
229 230
    {
      register Lisp_Object elt, tem;
231
      elt = XCAR (tail);
232 233 234 235 236 237 238
      tem = Fstring_equal (Fcar (elt), key);
      if (!NILP (tem))
	return elt;
    }
  return Qnil;
}

Paul Eggert's avatar
Paul Eggert committed
239
DEFUN ("get-buffer", Fget_buffer, Sget_buffer, 1, 1, 0,
240 241 242 243
       doc: /* Return the buffer named BUFFER-OR-NAME.
BUFFER-OR-NAME must be either a string or a buffer.  If BUFFER-OR-NAME
is a string and there is no buffer with that name, return nil.  If
BUFFER-OR-NAME is a buffer, return it as given.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
244
  (register Lisp_Object buffer_or_name)
Roland McGrath's avatar
Roland McGrath committed
245
{
246 247 248
  if (BUFFERP (buffer_or_name))
    return buffer_or_name;
  CHECK_STRING (buffer_or_name);
Roland McGrath's avatar
Roland McGrath committed
249

250
  return Fcdr (assoc_ignore_text_properties (buffer_or_name, Vbuffer_alist));
Roland McGrath's avatar
Roland McGrath committed
251 252 253
}

DEFUN ("get-file-buffer", Fget_file_buffer, Sget_file_buffer, 1, 1, 0,
254
       doc: /* Return the buffer visiting file FILENAME (a string).
Pavel Janík's avatar
Pavel Janík committed
255 256
The buffer's `buffer-file-name' must match exactly the expansion of FILENAME.
If there is no such live buffer, return nil.
257
See also `find-buffer-visiting'.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
258
  (register Lisp_Object filename)
Roland McGrath's avatar
Roland McGrath committed
259 260
{
  register Lisp_Object tail, buf, tem;
Richard M. Stallman's avatar
Richard M. Stallman committed
261 262
  Lisp_Object handler;

263
  CHECK_STRING (filename);
Roland McGrath's avatar
Roland McGrath committed
264 265
  filename = Fexpand_file_name (filename, Qnil);

Richard M. Stallman's avatar
Richard M. Stallman committed
266 267
  /* If the file name has special constructs in it,
     call the corresponding file handler.  */
268
  handler = Ffind_file_name_handler (filename, Qget_file_buffer);
Richard M. Stallman's avatar
Richard M. Stallman committed
269 270 271
  if (!NILP (handler))
    return call2 (handler, Qget_file_buffer, filename);

272
  for (tail = Vbuffer_alist; CONSP (tail); tail = XCDR (tail))
Roland McGrath's avatar
Roland McGrath committed
273
    {
274
      buf = Fcdr (XCAR (tail));
275
      if (!BUFFERP (buf)) continue;
Tom Tromey's avatar
Tom Tromey committed
276 277
      if (!STRINGP (BVAR (XBUFFER (buf), filename))) continue;
      tem = Fstring_equal (BVAR (XBUFFER (buf), filename), filename);
Jim Blandy's avatar
Jim Blandy committed
278
      if (!NILP (tem))
Roland McGrath's avatar
Roland McGrath committed
279 280 281 282 283
	return buf;
    }
  return Qnil;
}

284
Lisp_Object
285
get_truename_buffer (register Lisp_Object filename)
286 287 288
{
  register Lisp_Object tail, buf, tem;

289
  for (tail = Vbuffer_alist; CONSP (tail); tail = XCDR (tail))
290
    {
291
      buf = Fcdr (XCAR (tail));
292
      if (!BUFFERP (buf)) continue;
Tom Tromey's avatar
Tom Tromey committed
293 294
      if (!STRINGP (BVAR (XBUFFER (buf), file_truename))) continue;
      tem = Fstring_equal (BVAR (XBUFFER (buf), file_truename), filename);
295 296 297 298 299 300
      if (!NILP (tem))
	return buf;
    }
  return Qnil;
}

Paul Eggert's avatar
Paul Eggert committed
301
DEFUN ("get-buffer-create", Fget_buffer_create, Sget_buffer_create, 1, 1, 0,
302 303 304 305 306 307 308 309
       doc: /* Return the buffer specified by BUFFER-OR-NAME, creating a new one if needed.
If BUFFER-OR-NAME is a string and a live buffer with that name exists,
return that buffer.  If no such buffer exists, create a new buffer with
that name and return it.  If BUFFER-OR-NAME starts with a space, the new
buffer does not keep undo information.

If BUFFER-OR-NAME is a buffer instead of a string, return it as given,
even if it is dead.  The return value is never nil.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
310
  (register Lisp_Object buffer_or_name)
Roland McGrath's avatar
Roland McGrath committed
311
{
312
  register Lisp_Object buffer, name;
Roland McGrath's avatar
Roland McGrath committed
313 314
  register struct buffer *b;

315 316 317
  buffer = Fget_buffer (buffer_or_name);
  if (!NILP (buffer))
    return buffer;
Roland McGrath's avatar
Roland McGrath committed
318

319
  if (SCHARS (buffer_or_name) == 0)
320 321
    error ("Empty string for buffer name is not allowed");

322
  b = allocate_buffer ();
Roland McGrath's avatar
Roland McGrath committed
323

324 325 326 327
  /* An ordinary buffer uses its own struct buffer_text.  */
  b->text = &b->own_text;
  b->base_buffer = 0;

Roland McGrath's avatar
Roland McGrath committed
328
  BUF_GAP_SIZE (b) = 20;
329
  BLOCK_INPUT;
Karl Heuer's avatar
Karl Heuer committed
330 331
  /* We allocate extra 1-byte at the tail and keep it always '\0' for
     anchoring a search.  */
332
  alloc_buffer_text (b, BUF_GAP_SIZE (b) + 1);
333
  UNBLOCK_INPUT;
Roland McGrath's avatar
Roland McGrath committed
334
  if (! BUF_BEG_ADDR (b))
Paul Eggert's avatar
Paul Eggert committed
335
    buffer_memory_full (BUF_GAP_SIZE (b) + 1);
Roland McGrath's avatar
Roland McGrath committed
336

337 338 339 340 341 342 343
  b->pt = BEG;
  b->begv = BEG;
  b->zv = BEG;
  b->pt_byte = BEG_BYTE;
  b->begv_byte = BEG_BYTE;
  b->zv_byte = BEG_BYTE;

344 345
  BUF_GPT (b) = BEG;
  BUF_GPT_BYTE (b) = BEG_BYTE;
346 347

  BUF_Z (b) = BEG;
348
  BUF_Z_BYTE (b) = BEG_BYTE;
Roland McGrath's avatar
Roland McGrath committed
349
  BUF_MODIFF (b) = 1;
350
  BUF_CHARS_MODIFF (b) = 1;
351
  BUF_OVERLAY_MODIFF (b) = 1;
352 353
  BUF_SAVE_MODIFF (b) = 1;
  BUF_INTERVALS (b) = 0;
354 355 356 357
  BUF_UNCHANGED_MODIFIED (b) = 1;
  BUF_OVERLAY_UNCHANGED_MODIFIED (b) = 1;
  BUF_END_UNCHANGED (b) = 0;
  BUF_BEG_UNCHANGED (b) = 0;
Karl Heuer's avatar
Karl Heuer committed
358
  *(BUF_GPT_ADDR (b)) = *(BUF_Z_ADDR (b)) = 0; /* Put an anchor '\0'.  */
Roland McGrath's avatar
Roland McGrath committed
359

360 361
  b->newline_cache = 0;
  b->width_run_cache = 0;
Tom Tromey's avatar
Tom Tromey committed
362
  BVAR (b, width_table) = Qnil;
363
  b->prevent_redisplay_optimizations_p = 1;
364

Roland McGrath's avatar
Roland McGrath committed
365
  /* Put this on the chain of all buffers including killed ones.  */
366
  b->header.next.buffer = all_buffers;
Roland McGrath's avatar
Roland McGrath committed
367 368
  all_buffers = b;

369 370
  /* An ordinary buffer normally doesn't need markers
     to handle BEGV and ZV.  */
Tom Tromey's avatar
Tom Tromey committed
371 372 373
  BVAR (b, pt_marker) = Qnil;
  BVAR (b, begv_marker) = Qnil;
  BVAR (b, zv_marker) = Qnil;
374

375
  name = Fcopy_sequence (buffer_or_name);
376
  STRING_SET_INTERVALS (name, NULL_INTERVAL);
Tom Tromey's avatar
Tom Tromey committed
377
  BVAR (b, name) = name;
378

Tom Tromey's avatar
Tom Tromey committed
379
  BVAR (b, undo_list) = (SREF (name, 0) != ' ') ? Qnil : Qt;
Roland McGrath's avatar
Roland McGrath committed
380 381

  reset_buffer (b);
382
  reset_buffer_local_variables (b, 1);
Roland McGrath's avatar
Roland McGrath committed
383

Tom Tromey's avatar
Tom Tromey committed
384
  BVAR (b, mark) = Fmake_marker ();
385
  BUF_MARKERS (b) = NULL;
Tom Tromey's avatar
Tom Tromey committed
386
  BVAR (b, name) = name;
387

Roland McGrath's avatar
Roland McGrath committed
388
  /* Put this in the alist of all live buffers.  */
389 390
  XSETBUFFER (buffer, b);
  Vbuffer_alist = nconc2 (Vbuffer_alist, Fcons (Fcons (name, buffer), Qnil));
391 392 393
  /* And run buffer-list-update-hook.  */
  if (!NILP (Vrun_hooks))
    call1 (Vrun_hooks, Qbuffer_list_update_hook);
Roland McGrath's avatar
Roland McGrath committed
394

Juanma Barranquero's avatar
Juanma Barranquero committed
395
  /* An error in calling the function here (should someone redefine it)
Dave Love's avatar
Dave Love committed
396 397
     can lead to infinite regress until you run out of stack.  rms
     says that's not worth protecting against.  */
Dave Love's avatar
Dave Love committed
398
  if (!NILP (Ffboundp (Qucs_set_table_for_input)))
399 400
    /* buffer is on buffer-alist, so no gcpro.  */
    call1 (Qucs_set_table_for_input, buffer);
Dave Love's avatar
Dave Love committed
401

402
  return buffer;
403 404
}

405

406 407 408
/* Return a list of overlays which is a copy of the overlay list
   LIST, but for buffer B.  */

409
static struct Lisp_Overlay *
410
copy_overlays (struct buffer *b, struct Lisp_Overlay *list)
411
{
412 413
  Lisp_Object buffer;
  struct Lisp_Overlay *result = NULL, *tail = NULL;
414 415 416

  XSETBUFFER (buffer, b);

417
  for (; list; list = list->next)
418 419
    {
      Lisp_Object overlay, start, end, old_overlay;
420
      EMACS_INT charpos;
421

422
      XSETMISC (old_overlay, list);
423 424
      charpos = marker_position (OVERLAY_START (old_overlay));
      start = Fmake_marker ();
425
      Fset_marker (start, make_number (charpos), buffer);
426 427 428 429 430
      XMARKER (start)->insertion_type
	= XMARKER (OVERLAY_START (old_overlay))->insertion_type;

      charpos = marker_position (OVERLAY_END (old_overlay));
      end = Fmake_marker ();
431
      Fset_marker (end, make_number (charpos), buffer);
432 433 434 435 436 437 438 439
      XMARKER (end)->insertion_type
	= XMARKER (OVERLAY_END (old_overlay))->insertion_type;

      overlay = allocate_misc ();
      XMISCTYPE (overlay) = Lisp_Misc_Overlay;
      OVERLAY_START (overlay) = start;
      OVERLAY_END (overlay) = end;
      OVERLAY_PLIST (overlay) = Fcopy_sequence (OVERLAY_PLIST (old_overlay));
440
      XOVERLAY (overlay)->next = NULL;
441

442 443 444 445
      if (tail)
	tail = tail->next = XOVERLAY (overlay);
      else
	result = tail = XOVERLAY (overlay);
446 447
    }

448
  return result;
449
}
450

451

452 453 454 455 456 457 458 459
/* Clone per-buffer values of buffer FROM.

   Buffer TO gets the same per-buffer values as FROM, with the
   following exceptions: (1) TO's name is left untouched, (2) markers
   are copied and made to refer to TO, and (3) overlay lists are
   copied.  */

static void
460
clone_per_buffer_values (struct buffer *from, struct buffer *to)
461
{
462
  Lisp_Object to_buffer;
463 464 465
  int offset;

  XSETBUFFER (to_buffer, to);
466

467 468
  /* buffer-local Lisp variables start at `undo_list',
     tho only the ones from `name' on are GC'd normally.  */
469
  for (offset = PER_BUFFER_VAR_OFFSET (undo_list);
470 471 472 473 474
       offset < sizeof *to;
       offset += sizeof (Lisp_Object))
    {
      Lisp_Object obj;

475 476 477 478
      /* Don't touch the `name' which should be unique for every buffer.  */
      if (offset == PER_BUFFER_VAR_OFFSET (name))
	continue;

479
      obj = PER_BUFFER_VALUE (from, offset);
480
      if (MARKERP (obj) && XMARKER (obj)->buffer == from)
481 482 483 484 485 486 487 488 489 490
	{
	  struct Lisp_Marker *m = XMARKER (obj);
	  obj = Fmake_marker ();
	  XMARKER (obj)->insertion_type = m->insertion_type;
	  set_marker_both (obj, to_buffer, m->charpos, m->bytepos);
	}

      PER_BUFFER_VALUE (to, offset) = obj;
    }

491
  memcpy (to->local_flags, from->local_flags, sizeof to->local_flags);
492

493 494
  to->overlays_before = copy_overlays (to, from->overlays_before);
  to->overlays_after = copy_overlays (to, from->overlays_after);
495

496 497
  /* Get (a copy of) the alist of Lisp-level local variables of FROM
     and install that in TO.  */
Tom Tromey's avatar
Tom Tromey committed
498
  BVAR (to, local_var_alist) = buffer_lisp_local_variables (from);
499 500
}

501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547

/* If buffer B has markers to record PT, BEGV and ZV when it is not
   current, update these markers.  */

static void
record_buffer_markers (struct buffer *b)
{
  if (! NILP (BVAR (b, pt_marker)))
    {
      Lisp_Object buffer;

      eassert (!NILP (BVAR (b, begv_marker)));
      eassert (!NILP (BVAR (b, zv_marker)));

      XSETBUFFER (buffer, b);
      set_marker_both (BVAR (b, pt_marker), buffer, b->pt, b->pt_byte);
      set_marker_both (BVAR (b, begv_marker), buffer, b->begv, b->begv_byte);
      set_marker_both (BVAR (b, zv_marker), buffer, b->zv, b->zv_byte);
    }
}


/* If buffer B has markers to record PT, BEGV and ZV when it is not
   current, fetch these values into B->begv etc.  */

static void
fetch_buffer_markers (struct buffer *b)
{
  if (! NILP (BVAR (b, pt_marker)))
    {
      Lisp_Object m;

      eassert (!NILP (BVAR (b, begv_marker)));
      eassert (!NILP (BVAR (b, zv_marker)));

      m = BVAR (b, pt_marker);
      SET_BUF_PT_BOTH (b, marker_position (m), marker_byte_position (m));

      m = BVAR (b, begv_marker);
      SET_BUF_BEGV_BOTH (b, marker_position (m), marker_byte_position (m));

      m = BVAR (b, zv_marker);
      SET_BUF_ZV_BOTH (b, marker_position (m), marker_byte_position (m));
    }
}


548 549
DEFUN ("make-indirect-buffer", Fmake_indirect_buffer, Smake_indirect_buffer,
       2, 3,
550
       "bMake indirect buffer (to buffer): \nBName of indirect buffer: ",
551
       doc: /* Create and return an indirect buffer for buffer BASE-BUFFER, named NAME.
Kenichi Handa's avatar
Kenichi Handa committed
552
BASE-BUFFER should be a live buffer, or the name of an existing buffer.
Pavel Janík's avatar
Pavel Janík committed
553 554 555
NAME should be a string which is not the name of an existing buffer.
Optional argument CLONE non-nil means preserve BASE-BUFFER's state,
such as major and minor modes, in the indirect buffer.
556
CLONE nil means the indirect buffer's state is reset to default values.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
557
  (Lisp_Object base_buffer, Lisp_Object name, Lisp_Object clone)
558
{
Kenichi Handa's avatar
Kenichi Handa committed
559
  Lisp_Object buf, tem;
560
  struct buffer *b;
561

Kenichi Handa's avatar
Kenichi Handa committed
562
  CHECK_STRING (name);
563 564
  buf = Fget_buffer (name);
  if (!NILP (buf))
565
    error ("Buffer name `%s' is in use", SDATA (name));
566

Kenichi Handa's avatar
Kenichi Handa committed
567
  tem = base_buffer;
568 569
  base_buffer = Fget_buffer (base_buffer);
  if (NILP (base_buffer))
Kenichi Handa's avatar
Kenichi Handa committed
570
    error ("No such buffer: `%s'", SDATA (tem));
Tom Tromey's avatar
Tom Tromey committed
571
  if (NILP (BVAR (XBUFFER (base_buffer), name)))
Kenichi Handa's avatar
Kenichi Handa committed
572
    error ("Base buffer has been killed");
573

574
  if (SCHARS (name) == 0)
575 576
    error ("Empty string for buffer name is not allowed");

577
  b = allocate_buffer ();
578

579 580 581
  b->base_buffer = (XBUFFER (base_buffer)->base_buffer
		    ? XBUFFER (base_buffer)->base_buffer
		    : XBUFFER (base_buffer));
582 583 584 585

  /* Use the base buffer's text object.  */
  b->text = b->base_buffer->text;

586 587 588 589 590 591
  b->pt = b->base_buffer->pt;
  b->begv = b->base_buffer->begv;
  b->zv = b->base_buffer->zv;
  b->pt_byte = b->base_buffer->pt_byte;
  b->begv_byte = b->base_buffer->begv_byte;
  b->zv_byte = b->base_buffer->zv_byte;
592 593 594

  b->newline_cache = 0;
  b->width_run_cache = 0;
Tom Tromey's avatar
Tom Tromey committed
595
  BVAR (b, width_table) = Qnil;
596 597

  /* Put this on the chain of all buffers including killed ones.  */
598
  b->header.next.buffer = all_buffers;
599 600 601
  all_buffers = b;

  name = Fcopy_sequence (name);
602
  STRING_SET_INTERVALS (name, NULL_INTERVAL);
Tom Tromey's avatar
Tom Tromey committed
603
  BVAR (b, name) = name;
604 605

  reset_buffer (b);
606
  reset_buffer_local_variables (b, 1);
607 608 609 610 611

  /* Put this in the alist of all live buffers.  */
  XSETBUFFER (buf, b);
  Vbuffer_alist = nconc2 (Vbuffer_alist, Fcons (Fcons (name, buf), Qnil));

Tom Tromey's avatar
Tom Tromey committed
612 613
  BVAR (b, mark) = Fmake_marker ();
  BVAR (b, name) = name;
614

615
  /* The multibyte status belongs to the base buffer.  */
Tom Tromey's avatar
Tom Tromey committed
616
  BVAR (b, enable_multibyte_characters) = BVAR (b->base_buffer, enable_multibyte_characters);
617

618
  /* Make sure the base buffer has markers for its narrowing.  */
Tom Tromey's avatar
Tom Tromey committed
619
  if (NILP (BVAR (b->base_buffer, pt_marker)))
620
    {
621 622
      eassert (NILP (BVAR (b->base_buffer, begv_marker)));
      eassert (NILP (BVAR (b->base_buffer, zv_marker)));
623

Tom Tromey's avatar
Tom Tromey committed
624 625
      BVAR (b->base_buffer, pt_marker) = Fmake_marker ();
      set_marker_both (BVAR (b->base_buffer, pt_marker), base_buffer,
626 627 628
		       b->base_buffer->pt,
		       b->base_buffer->pt_byte);

Tom Tromey's avatar
Tom Tromey committed
629 630
      BVAR (b->base_buffer, begv_marker) = Fmake_marker ();
      set_marker_both (BVAR (b->base_buffer, begv_marker), base_buffer,
631 632 633
		       b->base_buffer->begv,
		       b->base_buffer->begv_byte);

Tom Tromey's avatar
Tom Tromey committed
634 635
      BVAR (b->base_buffer, zv_marker) = Fmake_marker ();
      set_marker_both (BVAR (b->base_buffer, zv_marker), base_buffer,
636 637
		       b->base_buffer->zv,
		       b->base_buffer->zv_byte);
Tom Tromey's avatar
Tom Tromey committed
638
      XMARKER (BVAR (b->base_buffer, zv_marker))->insertion_type = 1;
639 640
    }

641 642 643
  if (NILP (clone))
    {
      /* Give the indirect buffer markers for its narrowing.  */
Tom Tromey's avatar
Tom Tromey committed
644
      BVAR (b, pt_marker) = Fmake_marker ();
645
      set_marker_both (BVAR (b, pt_marker), buf, b->pt, b->pt_byte);
Tom Tromey's avatar
Tom Tromey committed
646
      BVAR (b, begv_marker) = Fmake_marker ();
647
      set_marker_both (BVAR (b, begv_marker), buf, b->begv, b->begv_byte);
Tom Tromey's avatar
Tom Tromey committed
648
      BVAR (b, zv_marker) = Fmake_marker ();
649
      set_marker_both (BVAR (b, zv_marker), buf, b->zv, b->zv_byte);
Tom Tromey's avatar
Tom Tromey committed
650
      XMARKER (BVAR (b, zv_marker))->insertion_type = 1;
651 652
    }
  else
653 654 655 656
    {
      struct buffer *old_b = current_buffer;

      clone_per_buffer_values (b->base_buffer, b);
Tom Tromey's avatar
Tom Tromey committed
657 658 659 660 661
      BVAR (b, filename) = Qnil;
      BVAR (b, file_truename) = Qnil;
      BVAR (b, display_count) = make_number (0);
      BVAR (b, backed_up) = Qnil;
      BVAR (b, auto_save_file_name) = Qnil;
662 663 664 665 666 667
      set_buffer_internal_1 (b);
      Fset (intern ("buffer-save-without-query"), Qnil);
      Fset (intern ("buffer-file-number"), Qnil);
      Fset (intern ("buffer-stale-function"), Qnil);
      set_buffer_internal_1 (old_b);
    }
668

669 670 671 672
  /* Run buffer-list-update-hook.  */
  if (!NILP (Vrun_hooks))
    call1 (Vrun_hooks, Qbuffer_list_update_hook);

673
  return buf;
Roland McGrath's avatar
Roland McGrath committed
674 675
}

676
void
677
delete_all_overlays (struct buffer *b)
678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698
{
  Lisp_Object overlay;

  /* `reset_buffer' blindly sets the list of overlays to NULL, so we
     have to empty the list, otherwise we end up with overlays that
     think they belong to this buffer while the buffer doesn't know about
     them any more.  */
  while (b->overlays_before)
    {
      XSETMISC (overlay, b->overlays_before);
      Fdelete_overlay (overlay);
    }
  while (b->overlays_after)
    {
      XSETMISC (overlay, b->overlays_after);
      Fdelete_overlay (overlay);
    }
  eassert (b->overlays_before == NULL);
  eassert (b->overlays_after == NULL);
}

699
/* Reinitialize everything about a buffer except its name and contents
Kenichi Handa's avatar
Kenichi Handa committed
700
   and local variables.
701 702 703 704
   If called on an already-initialized buffer, the list of overlays
   should be deleted before calling this function, otherwise we end up
   with overlays that claim to belong to the buffer but the buffer
   claims it doesn't belong to it.  */
Roland McGrath's avatar
Roland McGrath committed
705 706

void
707
reset_buffer (register struct buffer *b)
Roland McGrath's avatar
Roland McGrath committed
708
{
Tom Tromey's avatar
Tom Tromey committed
709 710 711
  BVAR (b, filename) = Qnil;
  BVAR (b, file_truename) = Qnil;
  BVAR (b, directory) = (current_buffer) ? BVAR (current_buffer, directory) : Qnil;
Roland McGrath's avatar
Roland McGrath committed
712
  b->modtime = 0;
713
  b->modtime_size = -1;
Tom Tromey's avatar
Tom Tromey committed
714
  XSETFASTINT (BVAR (b, save_length), 0);
Roland McGrath's avatar
Roland McGrath committed
715
  b->last_window_start = 1;
716
  /* It is more conservative to start out "changed" than "unchanged".  */
717 718
  b->clip_changed = 0;
  b->prevent_redisplay_optimizations_p = 1;
Tom Tromey's avatar
Tom Tromey committed
719
  BVAR (b, backed_up) = Qnil;
720
  BUF_AUTOSAVE_MODIFF (b) = 0;
721
  b->auto_save_failure_time = -1;
Tom Tromey's avatar
Tom Tromey committed
722 723
  BVAR (b, auto_save_file_name) = Qnil;
  BVAR (b, read_only) = Qnil;
724 725
  b->overlays_before = NULL;
  b->overlays_after = NULL;
726
  b->overlay_center = BEG;
Tom Tromey's avatar
Tom Tromey committed
727 728 729 730 731 732 733 734 735 736
  BVAR (b, mark_active) = Qnil;
  BVAR (b, point_before_scroll) = Qnil;
  BVAR (b, file_format) = Qnil;
  BVAR (b, auto_save_file_format) = Qt;
  BVAR (b, last_selected_window) = Qnil;
  XSETINT (BVAR (b, display_count), 0);
  BVAR (b, display_time) = Qnil;
  BVAR (b, enable_multibyte_characters) = BVAR (&buffer_defaults, enable_multibyte_characters);
  BVAR (b, cursor_type) = BVAR (&buffer_defaults, cursor_type);
  BVAR (b, extra_line_spacing) = BVAR (&buffer_defaults, extra_line_spacing);
737 738

  b->display_error_modiff = 0;
Roland McGrath's avatar
Roland McGrath committed
739 740
}

741 742 743
/* Reset buffer B's local variables info.
   Don't use this on a buffer that has already been in use;
   it does not treat permanent locals consistently.
744 745
   Instead, use Fkill_all_local_variables.

746
   If PERMANENT_TOO is 1, then we reset permanent
747 748
   buffer-local variables.  If PERMANENT_TOO is 0,
   we preserve those.  */
749

750
static void
751
reset_buffer_local_variables (register struct buffer *b, int permanent_too)
Roland McGrath's avatar
Roland McGrath committed
752 753
{
  register int offset;
754
  int i;
Roland McGrath's avatar
Roland McGrath committed
755 756 757 758 759

  /* Reset the major mode to Fundamental, together with all the
     things that depend on the major mode.
     default-major-mode is handled at a higher level.
     We ignore it here.  */
Tom Tromey's avatar
Tom Tromey committed
760 761 762 763
  BVAR (b, major_mode) = Qfundamental_mode;
  BVAR (b, keymap) = Qnil;
  BVAR (b, mode_name) = QSFundamental;
  BVAR (b, minor_modes) = Qnil;
764 765 766 767 768 769 770 771

  /* If the standard case table has been altered and invalidated,
     fix up its insides first.  */
  if (! (CHAR_TABLE_P (XCHAR_TABLE (Vascii_downcase_table)->extras[0])
	 && CHAR_TABLE_P (XCHAR_TABLE (Vascii_downcase_table)->extras[1])
	 && CHAR_TABLE_P (XCHAR_TABLE (Vascii_downcase_table)->extras[2])))
    Fset_standard_case_table (Vascii_downcase_table);

Tom Tromey's avatar
Tom Tromey committed
772 773 774 775 776
  BVAR (b, downcase_table) = Vascii_downcase_table;
  BVAR (b, upcase_table) = XCHAR_TABLE (Vascii_downcase_table)->extras[0];
  BVAR (b, case_canon_table) = XCHAR_TABLE (Vascii_downcase_table)->extras[1];
  BVAR (b, case_eqv_table) = XCHAR_TABLE (Vascii_downcase_table)->extras[2];
  BVAR (b, invisibility_spec) = Qt;
777

778
  /* Reset all (or most) per-buffer variables to their defaults.  */
779
  if (permanent_too)
Tom Tromey's avatar
Tom Tromey committed
780
    BVAR (b, local_var_alist) = Qnil;
781 782
  else
    {
783
      Lisp_Object tmp, prop, last = Qnil;
Tom Tromey's avatar
Tom Tromey committed
784
      for (tmp = BVAR (b, local_var_alist); CONSP (tmp); tmp = XCDR (tmp))
785
	if (!NILP (prop = Fget (XCAR (XCAR (tmp)), Qpermanent_local)))
786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812
	  {
	    /* If permanent-local, keep it.  */
	    last = tmp;
	    if (EQ (prop, Qpermanent_local_hook))
	      {
		/* This is a partially permanent hook variable.
		   Preserve only the elements that want to be preserved.  */
		Lisp_Object list, newlist;
		list = XCDR (XCAR (tmp));
		if (!CONSP (list))
		  newlist = list;
		else
		  for (newlist = Qnil; CONSP (list); list = XCDR (list))
		    {
		      Lisp_Object elt = XCAR (list);
		      /* Preserve element ELT if it's t,
			 if it is a function with a `permanent-local-hook' property,
			 or if it's not a symbol.  */
		      if (! SYMBOLP (elt)
			  || EQ (elt, Qt)
			  || !NILP (Fget (elt, Qpermanent_local_hook)))
			newlist = Fcons (elt, newlist);
		    }
		XSETCDR (XCAR (tmp), Fnreverse (newlist));
	      }
	  }
	/* Delete this local variable.  */
813
	else if (NILP (last))
Tom Tromey's avatar
Tom Tromey committed
814
	  BVAR (b, local_var_alist) = XCDR (tmp);
815 816 817 818
	else
	  XSETCDR (last, XCDR (tmp));
    }

819
  for (i = 0; i < last_per_buffer_idx; ++i)
820
    if (permanent_too || buffer_permanent_local_flags[i] == 0)
821
      SET_PER_BUFFER_VALUE_P (b, i, 0);
Roland McGrath's avatar
Roland McGrath committed
822 823 824 825

  /* For each slot that has a default value,
     copy that into the slot.  */

826 827 828
  /* buffer-local Lisp variables start at `undo_list',
     tho only the ones from `name' on are GC'd normally.  */
  for (offset = PER_BUFFER_VAR_OFFSET (undo_list);
829 830
       offset < sizeof *b;
       offset += sizeof (Lisp_Object))
831
    {
832
      int idx = PER_BUFFER_IDX (offset);
833 834
      if ((idx > 0
	   && (permanent_too
835
	       || buffer_permanent_local_flags[idx] == 0)))
836
	PER_BUFFER_VALUE (b, offset) = PER_BUFFER_DEFAULT (offset);
837
    }
Roland McGrath's avatar
Roland McGrath committed
838 839
}

Roland McGrath's avatar
Roland McGrath committed
840 841 842 843
/* We split this away from generate-new-buffer, because rename-buffer
   and set-visited-file-name ought to be able to use this to really
   rename the buffer properly.  */

Paul Eggert's avatar
Paul Eggert committed
844
DEF