buffer.h 31.1 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Header file for the buffer manipulation primitives.
2
   Copyright (C) 1985, 86, 93, 94, 95, 97, 1998, 1999 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
Jim Blandy's avatar
Jim Blandy committed
8
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
9 10 11 12 13 14 15 16 17
any later version.

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
along with GNU Emacs; see the file COPYING.  If not, write to
18 19
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
Jim Blandy's avatar
Jim Blandy committed
20 21


22
/* Accessing the parameters of the current buffer.  */
23

24 25
/* These macros come in pairs, one for the char position
   and one for the byte position.  */
Jim Blandy's avatar
Jim Blandy committed
26

27
/* Position of beginning of buffer.  */ 
Jim Blandy's avatar
Jim Blandy committed
28
#define BEG (1)
29
#define BEG_BYTE (1)
Jim Blandy's avatar
Jim Blandy committed
30

31
/* Position of beginning of accessible range of buffer.  */ 
32
#define BEGV (current_buffer->begv)
33
#define BEGV_BYTE (current_buffer->begv_byte)
Jim Blandy's avatar
Jim Blandy committed
34

35
/* Position of point in buffer.  The "+ 0" makes this
Jim Blandy's avatar
Jim Blandy committed
36
   not an l-value, so you can't assign to it.  Use SET_PT instead.  */ 
37
#define PT (current_buffer->pt + 0)
38
#define PT_BYTE (current_buffer->pt_byte + 0)
Jim Blandy's avatar
Jim Blandy committed
39

40
/* Position of gap in buffer.  */ 
41
#define GPT (current_buffer->text->gpt)
42
#define GPT_BYTE (current_buffer->text->gpt_byte)
Jim Blandy's avatar
Jim Blandy committed
43

44
/* Position of end of accessible range of buffer.  */ 
45
#define ZV (current_buffer->zv)
46
#define ZV_BYTE (current_buffer->zv_byte)
Jim Blandy's avatar
Jim Blandy committed
47

48
/* Position of end of buffer.  */ 
49
#define Z (current_buffer->text->z)
50
#define Z_BYTE (current_buffer->text->z_byte)
Jim Blandy's avatar
Jim Blandy committed
51

52
/* Macros for the addresses of places in the buffer.  */
Jim Blandy's avatar
Jim Blandy committed
53 54

/* Address of beginning of buffer.  */ 
55
#define BEG_ADDR (current_buffer->text->beg)
Jim Blandy's avatar
Jim Blandy committed
56 57

/* Address of beginning of accessible range of buffer.  */ 
58
#define BEGV_ADDR (BYTE_POS_ADDR (current_buffer->begv_byte))
Jim Blandy's avatar
Jim Blandy committed
59 60

/* Address of point in buffer.  */ 
61
#define PT_ADDR (BYTE_POS_ADDR (current_buffer->pt_byte))
Jim Blandy's avatar
Jim Blandy committed
62 63

/* Address of beginning of gap in buffer.  */ 
64
#define GPT_ADDR (current_buffer->text->beg + current_buffer->text->gpt_byte - 1)
Jim Blandy's avatar
Jim Blandy committed
65 66

/* Address of end of gap in buffer.  */
67
#define GAP_END_ADDR (current_buffer->text->beg + current_buffer->text->gpt_byte + current_buffer->text->gap_size - 1)
Jim Blandy's avatar
Jim Blandy committed
68 69

/* Address of end of accessible range of buffer.  */ 
70
#define ZV_ADDR (BYTE_POS_ADDR (current_buffer->zv_byte))
71 72

/* Address of end of buffer.  */ 
73
#define Z_ADDR (current_buffer->text->beg + current_buffer->text->gap_size + current_buffer->text->z_byte - 1)
Jim Blandy's avatar
Jim Blandy committed
74 75

/* Size of gap.  */
76
#define GAP_SIZE (current_buffer->text->gap_size)
Jim Blandy's avatar
Jim Blandy committed
77

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
/* Is the current buffer narrowed?  */
#define NARROWED	((BEGV != BEG) || (ZV != Z))

/* Modification count.  */
#define MODIFF (current_buffer->text->modiff)

/* Overlay modification count.  */
#define OVERLAY_MODIFF (current_buffer->text->overlay_modiff)

/* Modification count as of last visit or save.  */
#define SAVE_MODIFF (current_buffer->text->save_modiff)

/* BUFFER_CEILING_OF (resp. BUFFER_FLOOR_OF), when applied to n, return
   the max (resp. min) p such that

   BYTE_POS_ADDR (p) - BYTE_POS_ADDR (n) == p - n       */

#define BUFFER_CEILING_OF(BYTEPOS) \
  (((BYTEPOS) < GPT_BYTE && GPT < ZV ? GPT_BYTE : ZV_BYTE) - 1)
#define BUFFER_FLOOR_OF(BYTEPOS) \
  (BEGV <= GPT && GPT_BYTE <= (BYTEPOS) ? GPT_BYTE : BEGV_BYTE)

/* Similar macros to operate on a specified buffer.
Jim Blandy's avatar
Jim Blandy committed
101 102
   Note that many of these evaluate the buffer argument more than once.  */

103
/* Position of beginning of buffer.  */ 
Jim Blandy's avatar
Jim Blandy committed
104
#define BUF_BEG(buf) (1)
105
#define BUF_BEG_BYTE(buf) (1)
Jim Blandy's avatar
Jim Blandy committed
106

107
/* Position of beginning of accessible range of buffer.  */ 
108
#define BUF_BEGV(buf) ((buf)->begv)
109
#define BUF_BEGV_BYTE(buf) ((buf)->begv_byte)
Jim Blandy's avatar
Jim Blandy committed
110

111
/* Position of point in buffer.  */ 
112
#define BUF_PT(buf) ((buf)->pt)
113
#define BUF_PT_BYTE(buf) ((buf)->pt_byte)
Jim Blandy's avatar
Jim Blandy committed
114

115
/* Position of gap in buffer.  */ 
116
#define BUF_GPT(buf) ((buf)->text->gpt)
117
#define BUF_GPT_BYTE(buf) ((buf)->text->gpt_byte)
Jim Blandy's avatar
Jim Blandy committed
118

119
/* Position of end of accessible range of buffer.  */ 
120
#define BUF_ZV(buf) ((buf)->zv)
121
#define BUF_ZV_BYTE(buf) ((buf)->zv_byte)
Jim Blandy's avatar
Jim Blandy committed
122

123
/* Position of end of buffer.  */ 
124
#define BUF_Z(buf) ((buf)->text->z)
125 126 127 128 129 130 131 132 133 134 135 136 137
#define BUF_Z_BYTE(buf) ((buf)->text->z_byte)

/* Address of beginning of buffer.  */
#define BUF_BEG_ADDR(buf) ((buf)->text->beg)

/* Address of beginning of gap of buffer.  */
#define BUF_GPT_ADDR(buf) ((buf)->text->beg + (buf)->text->gpt_byte - 1)

/* Address of end of buffer.  */
#define BUF_Z_ADDR(buf) ((buf)->text->beg + (buf)->text->gap_size + (buf)->text->z_byte - 1)

/* Address of end of gap in buffer.  */
#define BUF_GAP_END_ADDR(buf) ((buf)->text->beg + (buf)->text->gpt_byte + (buf)->text->gap_size - 1)
Jim Blandy's avatar
Jim Blandy committed
138

139 140 141 142
/* Size of gap.  */
#define BUF_GAP_SIZE(buf) ((buf)->text->gap_size)

/* Is this buffer narrowed?  */
143 144
#define BUF_NARROWED(buf) ((BUF_BEGV (buf) != BUF_BEG (buf)) \
			   || (BUF_ZV (buf) != BUF_Z (buf)))
145

Jim Blandy's avatar
Jim Blandy committed
146
/* Modification count.  */
147 148 149 150 151
#define BUF_MODIFF(buf) ((buf)->text->modiff)

/* Modification count as of last visit or save.  */
#define BUF_SAVE_MODIFF(buf) ((buf)->text->save_modiff)

152 153 154
/* Overlay modification count.  */
#define BUF_OVERLAY_MODIFF(buf) ((buf)->text->overlay_modiff)

155 156 157 158 159
/* Interval tree of buffer.  */
#define BUF_INTERVALS(buf) ((buf)->text->intervals)

/* Marker chain of buffer.  */
#define BUF_MARKERS(buf) ((buf)->text->markers)
Gerd Moellmann's avatar
Gerd Moellmann committed
160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198

#define BUF_UNCHANGED_MODIFIED(buf) \
  ((buf)->text->unchanged_modified)

#define BUF_OVERLAY_UNCHANGED_MODIFIED(buf) \
  ((buf)->text->overlay_unchanged_modified)
#define BUF_BEG_UNCHANGED(buf) ((buf)->text->beg_unchanged)
#define BUF_END_UNCHANGED(buf) ((buf)->text->end_unchanged)

#define UNCHANGED_MODIFIED \
  BUF_UNCHANGED_MODIFIED (current_buffer)
#define OVERLAY_UNCHANGED_MODIFIED \
  BUF_OVERLAY_UNCHANGED_MODIFIED (current_buffer)
#define BEG_UNCHANGED BUF_BEG_UNCHANGED (current_buffer)
#define END_UNCHANGED BUF_END_UNCHANGED (current_buffer)

/* Compute how many characters at the top and bottom of BUF are
   unchanged when the range START..END is modified.  This computation
   must be done each time BUF is modified.  */

#define BUF_COMPUTE_UNCHANGED(buf, start, end)				\
  do									\
    {									\
      if (BUF_UNCHANGED_MODIFIED (buf) == MODIFF			\
	  && BUF_OVERLAY_UNCHANGED_MODIFIED (buf) == OVERLAY_MODIFF)	\
	{								\
	  BUF_BEG_UNCHANGED (buf) = (start) - BUF_BEG (buf);		\
	  BUF_END_UNCHANGED (buf) = BUF_Z (buf) - (end);		\
	}								\
      else								\
	{								\
	  if (BUF_Z (buf) - (end) < BUF_END_UNCHANGED (buf))		\
	    BUF_END_UNCHANGED (buf) = BUF_Z (buf) - (end);		\
	  if ((start) - BUF_BEG (buf) < BUF_BEG_UNCHANGED (buf))	\
	    BUF_BEG_UNCHANGED (buf) = (start) - BUF_BEG (buf);		\
	}								\
    }									\
  while (0)
     
199 200

/* Macros to set PT in the current buffer, or another buffer..  */
Jim Blandy's avatar
Jim Blandy committed
201

202 203
#define SET_PT(position) (set_point (current_buffer, (position)))
#define TEMP_SET_PT(position) (temp_set_point (current_buffer, (position)))
Jim Blandy's avatar
Jim Blandy committed
204

205 206 207 208
#define SET_PT_BOTH(position, byte) \
  (set_point_both (current_buffer, (position), (byte)))
#define TEMP_SET_PT_BOTH(position, byte) \
  (temp_set_point_both (current_buffer, (position), (byte)))
209

210 211 212 213
#define BUF_SET_PT(buffer, position) \
  (set_point ((buffer), (position)))
#define BUF_TEMP_SET_PT(buffer, position) \
  (temp_set_point ((buffer), (position)))
214

215 216 217 218
extern void set_point P_ ((struct buffer *, int));
extern INLINE void temp_set_point P_ ((struct buffer *, int));
extern void set_point_both P_ ((struct buffer *, int, int));
extern INLINE void temp_set_point_both P_ ((struct buffer *, int, int));
Jim Blandy's avatar
Jim Blandy committed
219

220 221 222 223 224 225 226 227 228 229

/* Macros for setting the BEGV, ZV or PT of a given buffer.

   SET_BUF_PT* seet to be redundant.  Get rid of them?

   The ..._BOTH macros take both a charpos and a bytepos,
   which must correspond to each other.

   The macros without ..._BOTH take just a charpos,
   and compute the bytepos from it.  */
Jim Blandy's avatar
Jim Blandy committed
230

231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336
#define SET_BUF_BEGV(buf, charpos)				 \
  ((buf)->begv_byte = buf_charpos_to_bytepos ((buf), (charpos)), \
   (buf)->begv = (charpos))

#define SET_BUF_ZV(buf, charpos)				\
  ((buf)->zv_byte = buf_charpos_to_bytepos ((buf), (charpos)),	\
   (buf)->zv = (charpos))

#define SET_BUF_BEGV_BOTH(buf, charpos, byte)		\
  ((buf)->begv = (charpos),				\
   (buf)->begv_byte = (byte))

#define SET_BUF_ZV_BOTH(buf, charpos, byte)		\
  ((buf)->zv = (charpos),				\
   (buf)->zv_byte = (byte))

#define SET_BUF_PT_BOTH(buf, charpos, byte)		\
  ((buf)->pt = (charpos),				\
   (buf)->pt_byte = (byte))

/* Macros to access a character or byte in the current buffer,
   or convert between a byte position and an address.
   These macros do not check that the position is in range.  */

/* Access a Lisp position value in POS,
   and store the charpos in CHARPOS and the bypepos in BYPEPOS.  */

#define DECODE_POSITION(charpos, bytepos, pos)			\
if (1)								\
  {								\
    Lisp_Object __pos = (pos);					\
    if (NUMBERP (__pos))					\
      {								\
	charpos = __pos;					\
	bytepos = buf_charpos_to_bytepos (current_buffer, __pos);  \
      }								\
    else if (MARKERP (__pos))					\
      {								\
	charpos = marker_position (__pos);			\
	bytepos = marker_byte_position (__pos);			\
      }								\
    else							\
      wrong_type_argument (Qinteger_or_marker_p, __pos);	\
  }								\
else

/* Return the address of byte position N in current buffer.  */

#define BYTE_POS_ADDR(n) \
  (((n) >= GPT_BYTE ? GAP_SIZE : 0) + (n) + BEG_ADDR - 1)

/* Return the address of char position N.  */

#define CHAR_POS_ADDR(n)			\
  (((n) >= GPT ? GAP_SIZE : 0)			\
   + buf_charpos_to_bytepos (current_buffer, n)	\
   + BEG_ADDR - 1)

/* Convert a character position to a byte position.  */

#define CHAR_TO_BYTE(charpos)			\
  (buf_charpos_to_bytepos (current_buffer, charpos))

/* Convert a byte position to a character position.  */

#define BYTE_TO_CHAR(bytepos)			\
  (buf_bytepos_to_charpos (current_buffer, bytepos))

/* Convert PTR, the address of a byte in the buffer, into a byte position.  */

#define PTR_BYTE_POS(ptr) \
((ptr) - (current_buffer)->text->beg					    \
 - (ptr - (current_buffer)->text->beg < (unsigned) GPT_BYTE ? 0 : GAP_SIZE) \
 + 1)

/* Return character at position POS.  */

#define FETCH_CHAR(pos)				      	\
  (!NILP (current_buffer->enable_multibyte_characters)	\
   ? FETCH_MULTIBYTE_CHAR ((pos))		      	\
   : FETCH_BYTE ((pos)))

/* Return the byte at byte position N.  */

#define FETCH_BYTE(n) *(BYTE_POS_ADDR ((n)))

/* Variables used locally in FETCH_MULTIBYTE_CHAR.  */
extern unsigned char *_fetch_multibyte_char_p;
extern int _fetch_multibyte_char_len;

/* Return character code of multi-byte form at position POS.  If POS
   doesn't point the head of valid multi-byte form, only the byte at
   POS is returned.  No range checking.  */

#define FETCH_MULTIBYTE_CHAR(pos)				 	\
  (_fetch_multibyte_char_p = (((pos) >= GPT_BYTE ? GAP_SIZE : 0) 	\
			       + (pos) + BEG_ADDR - 1),		 	\
   _fetch_multibyte_char_len						\
      = ((pos) >= GPT_BYTE ? ZV_BYTE : GPT_BYTE) - (pos),		\
   STRING_CHAR (_fetch_multibyte_char_p, _fetch_multibyte_char_len))

/* Macros for accessing a character or byte,
   or converting between byte positions and addresses,
   in a specified buffer.  */

/* Return the address of character at byte position POS in buffer BUF. 
Jim Blandy's avatar
Jim Blandy committed
337
   Note that both arguments can be computed more than once.  */
338 339

#define BUF_BYTE_ADDRESS(buf, pos) \
340
((buf)->text->beg + (pos) - 1		\
341 342 343 344 345 346 347
 + ((pos) >= (buf)->text->gpt_byte ? (buf)->text->gap_size : 0))

/* Return the address of character at char position POS in buffer BUF. 
   Note that both arguments can be computed more than once.  */

#define BUF_CHAR_ADDRESS(buf, pos) \
((buf)->text->beg + buf_charpos_to_bytepos ((buf), (pos)) - 1	\
348
 + ((pos) >= (buf)->text->gpt ? (buf)->text->gap_size : 0))
Jim Blandy's avatar
Jim Blandy committed
349

350 351
/* Convert PTR, the address of a char in buffer BUF,
   into a character position.  */
352

353 354 355 356
#define BUF_PTR_BYTE_POS(buf, ptr)				\
((ptr) - (buf)->text->beg					\
 - (ptr - (buf)->text->beg < (unsigned) BUF_GPT_BYTE ((buf))	\
    ? 0 : BUF_GAP_SIZE ((buf)))					\
357
 + 1)
358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382

/* Return the character at byte position POS in buffer BUF.   */

#define BUF_FETCH_CHAR(buf, pos)	      	\
  (!NILP (buf->enable_multibyte_characters)	\
   ? BUF_FETCH_MULTIBYTE_CHAR ((buf), (pos))    \
   : BUF_FETCH_BYTE ((buf), (pos)))

/* Return the byte at byte position N in buffer BUF.   */

#define BUF_FETCH_BYTE(buf, n) \
  *(BUF_BYTE_ADDRESS ((buf), (n)))

/* Return character code of multi-byte form at byte position POS in BUF.
   If POS doesn't point the head of valid multi-byte form, only the byte at
   POS is returned.  No range checking.  */

#define BUF_FETCH_MULTIBYTE_CHAR(buf, pos)				\
  (_fetch_multibyte_char_p						\
     = (((pos) >= BUF_GPT_BYTE (buf) ? BUF_GAP_SIZE (buf) : 0)		\
        + (pos) + BUF_BEG_ADDR (buf) - 1),				\
   _fetch_multibyte_char_len						\
     = (((pos) >= BUF_GPT_BYTE (buf) ? BUF_ZV_BYTE (buf) : BUF_GPT_BYTE (buf)) \
        - (pos)),							\
   STRING_CHAR (_fetch_multibyte_char_p, _fetch_multibyte_char_len))
Jim Blandy's avatar
Jim Blandy committed
383

384 385 386 387 388
/* Define the actual buffer data structures.  */

/* This data structure describes the actual text contents of a buffer.
   It is shared between indirect buffers and their base buffer.  */

Jim Blandy's avatar
Jim Blandy committed
389 390
struct buffer_text
  {
391
    unsigned char *beg;		/* Actual address of buffer contents.  */
392 393 394 395
    int gpt;			/* Char pos of gap in buffer.  */
    int z;			/* Char pos of end of buffer.  */
    int gpt_byte;		/* Byte pos of gap in buffer.  */
    int z_byte;			/* Byte pos of end of buffer.  */
396
    int gap_size;		/* Size of buffer's gap.  */
Jim Blandy's avatar
Jim Blandy committed
397 398 399 400
    int modiff;			/* This counts buffer-modification events
				   for this buffer.  It is incremented for
				   each such event, and never otherwise
				   changed.  */
401 402 403
    int save_modiff;		/* Previous value of modiff, as of last
				   time buffer visited or saved a file.  */

404 405
    int overlay_modiff;		/* Counts modifications to overlays.  */

Gerd Moellmann's avatar
Gerd Moellmann committed
406 407 408 409 410 411 412 413 414 415 416 417 418 419 420
    /* Minimum value of GPT - BEG since last redisplay that finished.  */
    int beg_unchanged;

    /* Minimum value of Z - GPT since last redisplay that finished.  */
    int end_unchanged;

    /* MODIFF as of last redisplay that finished; if it matches MODIFF,
       beg_unchanged and end_unchanged contain no useful information.  */
    int unchanged_modified;

    /* BUF_OVERLAY_MODIFF of current buffer, as of last redisplay that
       finished; if it matches BUF_OVERLAY_MODIFF, beg_unchanged and
       end_unchanged contain no useful information.  */
    int overlay_unchanged_modified;

421 422 423 424 425 426 427 428
    /* Properties of this buffer's text -- conditionally compiled.  */
    DECLARE_INTERVALS

    /* The markers that refer to this buffer.
       This is actually a single marker ---
       successive elements in its marker `chain'
       are the other markers referring to this buffer.  */
    Lisp_Object markers;
Jim Blandy's avatar
Jim Blandy committed
429 430
  };

431 432
/* This is the structure that the buffer Lisp object points to.  */

Jim Blandy's avatar
Jim Blandy committed
433 434 435 436 437
struct buffer
  {
    /* Everything before the `name' slot must be of a non-Lisp_Object type,
       and every slot after `name' must be a Lisp_Object.

438 439 440
       Check out mark_buffer (alloc.c) to see why.  */

    EMACS_INT size;
Jim Blandy's avatar
Jim Blandy committed
441 442 443

    /* Next buffer, in chain of all buffers including killed buffers.
       This chain is used only for garbage collection, in order to
444 445 446
       collect killed buffers properly.
       Note that vectors and most pseudovectors are all on one chain,
       but buffers are on a separate chain of their own.  */
Jim Blandy's avatar
Jim Blandy committed
447
    struct buffer *next;
448 449 450 451 452 453 454 455 456 457

    /* This structure holds the coordinates of the buffer contents
       in ordinary buffers.  In indirect buffers, this is not used.  */
    struct buffer_text own_text;

    /* This points to the `struct buffer_text' that used for this buffer.
       In an ordinary buffer, this is the own_text field above.
       In an indirect buffer, this is the own_text field of another buffer.  */
    struct buffer_text *text;

458
    /* Char position of point in buffer.  */
459
    int pt;
460 461 462
    /* Byte position of point in buffer.  */
    int pt_byte;
    /* Char position of beginning of accessible range.  */
463
    int begv;
464 465 466
    /* Byte position of beginning of accessible range.  */
    int begv_byte;
    /* Char position of end of accessible range.  */
467
    int zv;
468 469
    /* Byte position of end of accessible range.  */
    int zv_byte;
470 471 472 473 474

    /* In an indirect buffer, this points to the base buffer.
       In an ordinary buffer, it is 0.  */
    struct buffer *base_buffer;

Jim Blandy's avatar
Jim Blandy committed
475 476 477 478 479 480 481 482
    /* Flags saying which DEFVAR_PER_BUFFER variables
       are local to this buffer.  */
    int local_var_flags;
    /* Set to the modtime of the visited file when read or written.
       -1 means visited file was nonexistent.
       0 means visited file modtime unknown; in no case complain
       about any mismatch on next save attempt.  */
    int modtime;
483
    /* the value of text->modiff at the last auto-save.  */
Jim Blandy's avatar
Jim Blandy committed
484
    int auto_save_modified;
485 486 487
    /* The time at which we detected a failure to auto-save,
       Or -1 if we didn't have a failure.  */
    int auto_save_failure_time;
Jim Blandy's avatar
Jim Blandy committed
488
    /* Position in buffer at which display started
489
       the last time this buffer was displayed.  */
Jim Blandy's avatar
Jim Blandy committed
490 491
    int last_window_start;

492 493 494
    /* Set nonzero whenever the narrowing is changed in this buffer.  */
    int clip_changed;

495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512
    /* If the long line scan cache is enabled (i.e. the buffer-local
       variable cache-long-line-scans is non-nil), newline_cache
       points to the newline cache, and width_run_cache points to the
       width run cache.

       The newline cache records which stretches of the buffer are
       known *not* to contain newlines, so that they can be skipped
       quickly when we search for newlines.

       The width run cache records which stretches of the buffer are
       known to contain characters whose widths are all the same.  If
       the width run cache maps a character to a value > 0, that value is
       the character's width; if it maps a character to zero, we don't
       know what its width is.  This allows compute_motion to process
       such regions very quickly, using algebra instead of inspecting
       each character.   See also width_table, below.  */
    struct region_cache *newline_cache;
    struct region_cache *width_run_cache;
Jim Blandy's avatar
Jim Blandy committed
513

Gerd Moellmann's avatar
Gerd Moellmann committed
514 515 516 517
    /* Non-zero means don't use redisplay optimizations for
       displaying this buffer.  */
    unsigned prevent_redisplay_optimizations_p : 1;

518 519 520 521 522 523 524 525 526
    /* Changes in the buffer are recorded here for undo.
       t means don't record anything.
       This information belongs to the base buffer of an indirect buffer,
       But we can't store it in the  struct buffer_text
       because local variables have to be right in the  struct buffer.
       So we copy it around in set_buffer_internal.
       This comes before `name' because it is marked in a special way.  */
    Lisp_Object undo_list;

Jim Blandy's avatar
Jim Blandy committed
527 528
    /* Everything from here down must be a Lisp_Object */

529
    /* The name of this buffer.  */
Jim Blandy's avatar
Jim Blandy committed
530
    Lisp_Object name;
Gerd Moellmann's avatar
Gerd Moellmann committed
531

532
    /* The name of the file visited in this buffer, or nil.  */
Jim Blandy's avatar
Jim Blandy committed
533
    Lisp_Object filename;
534
    /* Dir for expanding relative file names.  */
Jim Blandy's avatar
Jim Blandy committed
535
    Lisp_Object directory;
536 537 538
    /* True iff this buffer has been backed up (if you write to the
       visited file and it hasn't been backed up, then a backup will
       be made).  */
Jim Blandy's avatar
Jim Blandy committed
539 540
    /* This isn't really used by the C code, so could be deleted.  */
    Lisp_Object backed_up;
541 542 543
    /* Length of file when last read or saved.
       This is not in the  struct buffer_text
       because it's not used in indirect buffers at all.  */
Jim Blandy's avatar
Jim Blandy committed
544
    Lisp_Object save_length;
545 546 547
    /* File name used for auto-saving this buffer.
       This is not in the  struct buffer_text
       because it's not used in indirect buffers at all.  */
Jim Blandy's avatar
Jim Blandy committed
548
    Lisp_Object auto_save_file_name;
549 550

    /* Non-nil if buffer read-only.  */
Jim Blandy's avatar
Jim Blandy committed
551
    Lisp_Object read_only;
552 553
    /* "The mark".  This is a marker which may
       point into this buffer or may point nowhere.  */
Jim Blandy's avatar
Jim Blandy committed
554 555 556 557 558 559
    Lisp_Object mark;

    /* Alist of elements (SYMBOL . VALUE-IN-THIS-BUFFER)
       for all per-buffer variables of this buffer.  */
    Lisp_Object local_var_alist;

560
    /* Symbol naming major mode (eg, lisp-mode).  */
Jim Blandy's avatar
Jim Blandy committed
561
    Lisp_Object major_mode;
562
    /* Pretty name of major mode (eg, "Lisp"). */
Jim Blandy's avatar
Jim Blandy committed
563
    Lisp_Object mode_name;
564
    /* Mode line element that controls format of mode line.  */
Jim Blandy's avatar
Jim Blandy committed
565
    Lisp_Object mode_line_format;
Gerd Moellmann's avatar
Gerd Moellmann committed
566 567 568
    
    /* Analogous to mode_line_format for the line displayed at the top
       of windows.  Nil means don't display that line.  */
Gerd Moellmann's avatar
Change  
Gerd Moellmann committed
569
    Lisp_Object header_line_format;
Jim Blandy's avatar
Jim Blandy committed
570

571
    /* Keys that are bound local to this buffer.  */
Jim Blandy's avatar
Jim Blandy committed
572
    Lisp_Object keymap;
573
    /* This buffer's local abbrev table.  */
Jim Blandy's avatar
Jim Blandy committed
574
    Lisp_Object abbrev_table;
575
    /* This buffer's syntax table.  */
Jim Blandy's avatar
Jim Blandy committed
576
    Lisp_Object syntax_table;
577 578
    /* This buffer's category table.  */
    Lisp_Object category_table;
Jim Blandy's avatar
Jim Blandy committed
579 580 581 582 583 584 585 586

    /* Values of several buffer-local variables */
    /* tab-width is buffer-local so that redisplay can find it
       in buffers that are not current */
    Lisp_Object case_fold_search;
    Lisp_Object tab_width;
    Lisp_Object fill_column;
    Lisp_Object left_margin;
587
    /* Function to call when insert space past fill column.  */
Jim Blandy's avatar
Jim Blandy committed
588
    Lisp_Object auto_fill_function;
589 590
    /* nil: text, t: binary.
       This value is meaningful only on certain operating systems.  */
591 592 593
    /* Actually, we don't need this flag any more because end-of-line
       is handled correctly according to the buffer-file-coding-system
       of the buffer.  Just keeping it for backward compatibility.  */
594
    Lisp_Object buffer_file_type;
Jim Blandy's avatar
Jim Blandy committed
595

Richard M. Stallman's avatar
Richard M. Stallman committed
596 597
    /* Case table for case-conversion in this buffer.
       This char-table maps each char into its lower-case version.  */
Jim Blandy's avatar
Jim Blandy committed
598
    Lisp_Object downcase_table;
Richard M. Stallman's avatar
Richard M. Stallman committed
599
    /* Char-table mapping each char to its upper-case version.  */
Jim Blandy's avatar
Jim Blandy committed
600
    Lisp_Object upcase_table;
Richard M. Stallman's avatar
Richard M. Stallman committed
601
    /* Char-table for conversion for case-folding search.  */
602
    Lisp_Object case_canon_table;
Richard M. Stallman's avatar
Richard M. Stallman committed
603
    /* Char-table of equivalences for case-folding search.  */
604
    Lisp_Object case_eqv_table;
Jim Blandy's avatar
Jim Blandy committed
605

606
    /* Non-nil means do not display continuation lines.  */
Jim Blandy's avatar
Jim Blandy committed
607
    Lisp_Object truncate_lines;
608
    /* Non-nil means display ctl chars with uparrow.  */
Jim Blandy's avatar
Jim Blandy committed
609
    Lisp_Object ctl_arrow;
610 611
    /* Non-nil means display text from right to left.  */
    Lisp_Object direction_reversed;
Jim Blandy's avatar
Jim Blandy committed
612
    /* Non-nil means do selective display;
613
       see doc string in syms_of_buffer (buffer.c) for details.  */
Jim Blandy's avatar
Jim Blandy committed
614 615 616 617 618
    Lisp_Object selective_display;
#ifndef old
    /* Non-nil means show ... at end of line followed by invisible lines.  */
    Lisp_Object selective_display_ellipses;
#endif
619
    /* Alist of (FUNCTION . STRING) for each minor mode enabled in buffer.  */
Jim Blandy's avatar
Jim Blandy committed
620
    Lisp_Object minor_modes;
621 622
    /* t if "self-insertion" should overwrite; `binary' if it should also
       overwrite newlines and tabs - for editing executables and the like.  */
Jim Blandy's avatar
Jim Blandy committed
623
    Lisp_Object overwrite_mode;
624
    /* non-nil means abbrev mode is on.  Expand abbrevs automatically.  */
Jim Blandy's avatar
Jim Blandy committed
625
    Lisp_Object abbrev_mode;
626
    /* Display table to use for text in this buffer.  */
Jim Blandy's avatar
Jim Blandy committed
627
    Lisp_Object display_table;
628 629
    /* t means the mark and region are currently active.  */
    Lisp_Object mark_active;
Jim Blandy's avatar
Jim Blandy committed
630

631 632 633 634 635 636 637 638 639 640
    /* List of overlays that end at or before the current center,
       in order of end-position.  */
    Lisp_Object overlays_before;

    /* List of overlays that end after  the current center,
       in order of start-position.  */
    Lisp_Object overlays_after;

    /* Position where the overlay lists are centered.  */
    Lisp_Object overlay_center;
641

642 643 644 645
    /* Non-nil means the buffer contents are regarded as multi-byte
       form of characters, not a binary code.  */
    Lisp_Object enable_multibyte_characters;

646 647 648 649
    /* Coding system to be used for encoding the buffer contents on
       saving.  */
    Lisp_Object buffer_file_coding_system;

Karl Heuer's avatar
Karl Heuer committed
650
    /* List of symbols naming the file format used for visited file. */
651 652
    Lisp_Object file_format;

653 654 655 656 657 658 659 660 661
    /* True if the newline position cache and width run cache are
       enabled.  See search.c and indent.c.  */
    Lisp_Object cache_long_line_scans;

    /* If the width run cache is enabled, this table contains the
       character widths width_run_cache (see above) assumes.  When we
       do a thorough redisplay, we compare this against the buffer's
       current display table to see whether the display table has
       affected the widths of any characters.  If it has, we
662
       invalidate the width run cache, and re-initialize width_table.  */
663
    Lisp_Object width_table;
664 665 666 667 668 669 670 671 672 673 674 675 676 677 678

    /* In an indirect buffer, or a buffer that is the base of an
       indirect buffer, this holds a marker that records
       PT for this buffer when the buffer is not current.  */
    Lisp_Object pt_marker;

    /* In an indirect buffer, or a buffer that is the base of an
       indirect buffer, this holds a marker that records
       BEGV for this buffer when the buffer is not current.  */
    Lisp_Object begv_marker;

    /* In an indirect buffer, or a buffer that is the base of an
       indirect buffer, this holds a marker that records
       ZV for this buffer when the buffer is not current.  */
    Lisp_Object zv_marker;
679 680 681 682

    /* This holds the point value before the last scroll operation.
       Explicitly setting point sets this to nil.  */
    Lisp_Object point_before_scroll;
683 684 685

    /* Truename of the visited file, or nil.  */
    Lisp_Object file_truename;
686 687 688 689 690 691

    /* Invisibility spec of this buffer.
       t => any non-nil `invisible' property means invisible.
       A list => `invisible' property means invisible
                 if it is memq in that list.  */
    Lisp_Object invisibility_spec;
692

693 694 695 696
    /* This is the last window that was selected with this buffer in it,
       or nil if that window no longer displays this buffer.  */
    Lisp_Object last_selected_window;

697 698 699
    /* Incremented each time the buffer is displayed in a window.  */
    Lisp_Object display_count;
 
Gerd Moellmann's avatar
Gerd Moellmann committed
700 701 702 703 704 705 706 707
    /* Widths of left and right marginal areas for windows displaying
       this buffer.  */
    Lisp_Object left_margin_width, right_margin_width;

    /* Non-nil means indicate lines not displaying text (in a style
       like vi).  */
    Lisp_Object indicate_empty_lines;

708 709 710
    /* Time stamp updated each time this buffer is displayed in a window.  */
    Lisp_Object display_time;

Gerd Moellmann's avatar
Gerd Moellmann committed
711 712 713 714 715 716 717 718 719 720 721 722
    /* If scrolling the display because point is below the bottom of a
       window showing this buffer, try to choose a window start so
       that point ends up this number of lines from the top of the
       window.  Nil means that scrolling method isn't used.  */
    Lisp_Object scroll_up_aggressively;
    
    /* If scrolling the display because point is above the top of a
       window showing this buffer, try to choose a window start so
       that point ends up this number of lines from the bottom of the
       window.  Nil means that scrolling method isn't used.  */
    Lisp_Object scroll_down_aggressively;

723 724
    /* These are so we don't have to recompile everything
       the next few times we add a new slot.  */
725
    Lisp_Object extra2, extra3;
726
  };
727 728

/* This points to the current buffer.  */
Jim Blandy's avatar
Jim Blandy committed
729 730 731 732

extern struct buffer *current_buffer;

/* This structure holds the default values of the buffer-local variables
733
   that have special slots in each buffer.
Jim Blandy's avatar
Jim Blandy committed
734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750
   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.  */

extern struct buffer buffer_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,
   the bit for that slot (found in the same slot in this structure)
   is turned on in the buffer's local_var_flags slot.

   If a slot in this structure is zero, then even though there may
751
   be a Lisp-level local variable for the slot, it has no default value,
Jim Blandy's avatar
Jim Blandy committed
752 753 754 755 756 757 758 759 760 761
   and the corresponding slot in buffer_defaults is not used.  */

extern struct buffer buffer_local_flags;

/* For each buffer slot, this points to the Lisp symbol name
   for that slot in the current buffer.  It is 0 for slots
   that don't have such names.  */

extern struct buffer buffer_local_symbols;

Jim Blandy's avatar
Jim Blandy committed
762 763 764 765
/* This structure holds the required types for the values in the
   buffer-local slots.  If a slot contains Qnil, then the
   corresponding buffer slot may contain a value of any type.  If a
   slot contains an integer, then prospective values' tags must be
Karl Heuer's avatar
Karl Heuer committed
766 767 768 769 770 771
   equal to that integer (except nil is always allowed).
   When a tag does not match, the function
   buffer_slot_type_mismatch will signal an error.

   If a slot here contains -1, the corresponding variable is read-only.  */

772
extern struct buffer buffer_local_types;
773

774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792
extern void reset_buffer P_ ((struct buffer *));
extern void evaporate_overlays P_ ((int));
extern int overlays_at P_ ((int, int, Lisp_Object **, int *, int *, int *));
extern int sort_overlays P_ ((Lisp_Object *, int, struct window *));
extern void recenter_overlay_lists P_ ((struct buffer *, int));
extern int overlay_strings P_ ((int, struct window *, unsigned char **));
extern void validate_region P_ ((Lisp_Object *, Lisp_Object *));
extern void set_buffer_internal P_ ((struct buffer *));
extern void set_buffer_internal_1 P_ ((struct buffer *));
extern void set_buffer_temp P_ ((struct buffer *));
extern void record_buffer P_ ((Lisp_Object));
extern void buffer_slot_type_mismatch P_ ((int));
extern void fix_overlays_before P_ ((struct buffer *, int, int));


EXFUN (Fbuffer_name, 1);
EXFUN (Fget_file_buffer, 1);
EXFUN (Fnext_overlay_change, 1);
EXFUN (Fdelete_overlay, 1);
793

794
/* Functions to call before and after each text change.  */
Jim Blandy's avatar
Jim Blandy committed
795 796
extern Lisp_Object Vbefore_change_function;
extern Lisp_Object Vafter_change_function;
797 798
extern Lisp_Object Vbefore_change_functions;
extern Lisp_Object Vafter_change_functions;
Jim Blandy's avatar
Jim Blandy committed
799
extern Lisp_Object Vfirst_change_hook;
800 801
extern Lisp_Object Qbefore_change_functions;
extern Lisp_Object Qafter_change_functions;
Jim Blandy's avatar
Jim Blandy committed
802
extern Lisp_Object Qfirst_change_hook;
Jim Blandy's avatar
Jim Blandy committed
803

804 805 806
/* If nonzero, all modification hooks are suppressed.  */
extern int inhibit_modification_hooks;

807 808
extern Lisp_Object Vdeactivate_mark;
extern Lisp_Object Vtransient_mark_mode;
809 810 811

/* Overlays */

812
/* 1 if the OV is an overlay object.  */
Jim Blandy's avatar
Jim Blandy committed
813
#define OVERLAY_VALID(OV) (OVERLAYP (OV))
Jim Blandy's avatar
Jim Blandy committed
814

815
/* Return the marker that stands for where OV starts in the buffer.  */
816
#define OVERLAY_START(OV) (XOVERLAY (OV)->start)
Jim Blandy's avatar
Jim Blandy committed
817

818
/* Return the marker that stands for where OV ends in the buffer.  */
819
#define OVERLAY_END(OV) (XOVERLAY (OV)->end)
Jim Blandy's avatar
Jim Blandy committed
820

821 822
/* Return the actual buffer position for the marker P.
   We assume you know which buffer it's pointing into.  */
Jim Blandy's avatar
Jim Blandy committed
823

824 825
#define OVERLAY_POSITION(P) \
 (GC_MARKERP (P) ? marker_position (P) : (abort (), 0))
Jim Blandy's avatar
Jim Blandy committed
826

827 828
/* Allocation of buffer text.  */

Jim Blandy's avatar
Jim Blandy committed
829
#ifdef REL_ALLOC
830 831 832

extern char *r_alloc P_ ((char **, unsigned long));
extern void r_alloc_free P_ ((char **ptr));
Gerd Moellmann's avatar
Gerd Moellmann committed
833
extern char *r_re_alloc P_ ((char **, unsigned long));
834 835 836 837 838 839

#define BUFFER_ALLOC(data,size) \
     ((unsigned char *) r_alloc ((char **)&data, (size)))
#define BUFFER_REALLOC(data,size) \
     ((unsigned char *) r_re_alloc ((char **) &data, (size)))
#define BUFFER_FREE(data) (r_alloc_free ((char **) &data))
Jim Blandy's avatar
Jim Blandy committed
840 841 842 843 844 845 846
#define R_ALLOC_DECLARE(var,data) (r_alloc_declare (&var, (data)))
#else
#define BUFFER_ALLOC(data,size) (data = (unsigned char *) malloc ((size)))
#define BUFFER_REALLOC(data,size) ((unsigned char *) realloc ((data), (size)))
#define BUFFER_FREE(data) (free ((data)))
#define R_ALLOC_DECLARE(var,data)
#endif
Gerd Moellmann's avatar
Gerd Moellmann committed
847