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[emacs.git] / src / buffer.h
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1 /* Header file for the buffer manipulation primitives.
3 Copyright (C) 1985, 1986, 1993, 1994, 1995, 1997, 1998, 1999, 2000,
4 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 This file is part of GNU Emacs.
9 GNU Emacs is free software: you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation, either version 3 of the License, or
12 (at your option) any later version.
14 GNU Emacs is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
23 /* Accessing the parameters of the current buffer. */
25 /* These macros come in pairs, one for the char position
26 and one for the byte position. */
28 /* Position of beginning of buffer. */
29 #define BEG (1)
30 #define BEG_BYTE (BEG)
32 /* Position of beginning of accessible range of buffer. */
33 #define BEGV (current_buffer->begv)
34 #define BEGV_BYTE (current_buffer->begv_byte)
36 /* Position of point in buffer. The "+ 0" makes this
37 not an l-value, so you can't assign to it. Use SET_PT instead. */
38 #define PT (current_buffer->pt + 0)
39 #define PT_BYTE (current_buffer->pt_byte + 0)
41 /* Position of gap in buffer. */
42 #define GPT (current_buffer->text->gpt)
43 #define GPT_BYTE (current_buffer->text->gpt_byte)
45 /* Position of end of accessible range of buffer. */
46 #define ZV (current_buffer->zv)
47 #define ZV_BYTE (current_buffer->zv_byte)
49 /* Position of end of buffer. */
50 #define Z (current_buffer->text->z)
51 #define Z_BYTE (current_buffer->text->z_byte)
53 /* Macros for the addresses of places in the buffer. */
55 /* Address of beginning of buffer. */
56 #define BEG_ADDR (current_buffer->text->beg)
58 /* Address of beginning of accessible range of buffer. */
59 #define BEGV_ADDR (BYTE_POS_ADDR (current_buffer->begv_byte))
61 /* Address of point in buffer. */
62 #define PT_ADDR (BYTE_POS_ADDR (current_buffer->pt_byte))
64 /* Address of beginning of gap in buffer. */
65 #define GPT_ADDR (current_buffer->text->beg + current_buffer->text->gpt_byte - BEG_BYTE)
67 /* Address of end of gap in buffer. */
68 #define GAP_END_ADDR (current_buffer->text->beg + current_buffer->text->gpt_byte + current_buffer->text->gap_size - BEG_BYTE)
70 /* Address of end of accessible range of buffer. */
71 #define ZV_ADDR (BYTE_POS_ADDR (current_buffer->zv_byte))
73 /* Address of end of buffer. */
74 #define Z_ADDR (current_buffer->text->beg + current_buffer->text->gap_size + current_buffer->text->z_byte - BEG_BYTE)
76 /* Size of gap. */
77 #define GAP_SIZE (current_buffer->text->gap_size)
79 /* Is the current buffer narrowed? */
80 #define NARROWED ((BEGV != BEG) || (ZV != Z))
82 /* Modification count. */
83 #define MODIFF (current_buffer->text->modiff)
85 /* Character modification count. */
86 #define CHARS_MODIFF (current_buffer->text->chars_modiff)
88 /* Overlay modification count. */
89 #define OVERLAY_MODIFF (current_buffer->text->overlay_modiff)
91 /* Modification count as of last visit or save. */
92 #define SAVE_MODIFF (current_buffer->text->save_modiff)
94 /* BUFFER_CEILING_OF (resp. BUFFER_FLOOR_OF), when applied to n, return
95 the max (resp. min) p such that
97 BYTE_POS_ADDR (p) - BYTE_POS_ADDR (n) == p - n */
99 #define BUFFER_CEILING_OF(BYTEPOS) \
100 (((BYTEPOS) < GPT_BYTE && GPT < ZV ? GPT_BYTE : ZV_BYTE) - 1)
101 #define BUFFER_FLOOR_OF(BYTEPOS) \
102 (BEGV <= GPT && GPT_BYTE <= (BYTEPOS) ? GPT_BYTE : BEGV_BYTE)
104 /* Similar macros to operate on a specified buffer.
105 Note that many of these evaluate the buffer argument more than once. */
107 /* Position of beginning of buffer. */
108 #define BUF_BEG(buf) (BEG)
109 #define BUF_BEG_BYTE(buf) (BEG_BYTE)
111 /* !!!FIXME: all the BUF_BEGV/BUF_ZV/BUF_PT macros are flawed:
112 on indirect (or base) buffers, that value is only correct if that buffer
113 is the current_buffer, or if the buffer's text hasn't been modified (via
114 an indirect buffer) since it was last current. */
116 /* Position of beginning of accessible range of buffer. */
117 #define BUF_BEGV(buf) ((buf)->begv)
118 #define BUF_BEGV_BYTE(buf) ((buf)->begv_byte)
120 /* Position of point in buffer. */
121 #define BUF_PT(buf) ((buf)->pt)
122 #define BUF_PT_BYTE(buf) ((buf)->pt_byte)
124 /* Position of gap in buffer. */
125 #define BUF_GPT(buf) ((buf)->text->gpt)
126 #define BUF_GPT_BYTE(buf) ((buf)->text->gpt_byte)
128 /* Position of end of accessible range of buffer. */
129 #define BUF_ZV(buf) ((buf)->zv)
130 #define BUF_ZV_BYTE(buf) ((buf)->zv_byte)
132 /* Position of end of buffer. */
133 #define BUF_Z(buf) ((buf)->text->z)
134 #define BUF_Z_BYTE(buf) ((buf)->text->z_byte)
136 /* Address of beginning of buffer. */
137 #define BUF_BEG_ADDR(buf) ((buf)->text->beg)
139 /* Address of beginning of gap of buffer. */
140 #define BUF_GPT_ADDR(buf) ((buf)->text->beg + (buf)->text->gpt_byte - BEG_BYTE)
142 /* Address of end of buffer. */
143 #define BUF_Z_ADDR(buf) ((buf)->text->beg + (buf)->text->gap_size + (buf)->text->z_byte - BEG_BYTE)
145 /* Address of end of gap in buffer. */
146 #define BUF_GAP_END_ADDR(buf) ((buf)->text->beg + (buf)->text->gpt_byte + (buf)->text->gap_size - BEG_BYTE)
148 /* Size of gap. */
149 #define BUF_GAP_SIZE(buf) ((buf)->text->gap_size)
151 /* Is this buffer narrowed? */
152 #define BUF_NARROWED(buf) ((BUF_BEGV (buf) != BUF_BEG (buf)) \
153 || (BUF_ZV (buf) != BUF_Z (buf)))
155 /* Modification count. */
156 #define BUF_MODIFF(buf) ((buf)->text->modiff)
158 /* Character modification count. */
159 #define BUF_CHARS_MODIFF(buf) ((buf)->text->chars_modiff)
161 /* Modification count as of last visit or save. */
162 #define BUF_SAVE_MODIFF(buf) ((buf)->text->save_modiff)
164 /* Overlay modification count. */
165 #define BUF_OVERLAY_MODIFF(buf) ((buf)->text->overlay_modiff)
167 /* Modification count as of last auto-save. */
168 /* FIXME: should we move this into ->text->auto_save_modiff? */
169 #define BUF_AUTOSAVE_MODIFF(buf) ((buf)->auto_save_modified)
171 /* Interval tree of buffer. */
172 #define BUF_INTERVALS(buf) ((buf)->text->intervals)
174 /* Marker chain of buffer. */
175 #define BUF_MARKERS(buf) ((buf)->text->markers)
177 #define BUF_UNCHANGED_MODIFIED(buf) \
178 ((buf)->text->unchanged_modified)
180 #define BUF_OVERLAY_UNCHANGED_MODIFIED(buf) \
181 ((buf)->text->overlay_unchanged_modified)
182 #define BUF_BEG_UNCHANGED(buf) ((buf)->text->beg_unchanged)
183 #define BUF_END_UNCHANGED(buf) ((buf)->text->end_unchanged)
185 #define UNCHANGED_MODIFIED \
186 BUF_UNCHANGED_MODIFIED (current_buffer)
187 #define OVERLAY_UNCHANGED_MODIFIED \
188 BUF_OVERLAY_UNCHANGED_MODIFIED (current_buffer)
189 #define BEG_UNCHANGED BUF_BEG_UNCHANGED (current_buffer)
190 #define END_UNCHANGED BUF_END_UNCHANGED (current_buffer)
192 /* Compute how many characters at the top and bottom of BUF are
193 unchanged when the range START..END is modified. This computation
194 must be done each time BUF is modified. */
196 #define BUF_COMPUTE_UNCHANGED(buf, start, end) \
197 do \
199 if (BUF_UNCHANGED_MODIFIED (buf) == BUF_MODIFF (buf) \
200 && (BUF_OVERLAY_UNCHANGED_MODIFIED (buf) \
201 == BUF_OVERLAY_MODIFF (buf))) \
203 BUF_BEG_UNCHANGED (buf) = (start) - BUF_BEG (buf); \
204 BUF_END_UNCHANGED (buf) = BUF_Z (buf) - (end); \
206 else \
208 if (BUF_Z (buf) - (end) < BUF_END_UNCHANGED (buf)) \
209 BUF_END_UNCHANGED (buf) = BUF_Z (buf) - (end); \
210 if ((start) - BUF_BEG (buf) < BUF_BEG_UNCHANGED (buf)) \
211 BUF_BEG_UNCHANGED (buf) = (start) - BUF_BEG (buf); \
214 while (0)
217 /* Macros to set PT in the current buffer, or another buffer. */
219 #define SET_PT(position) (set_point (position))
220 #define TEMP_SET_PT(position) (temp_set_point (current_buffer, (position)))
222 #define SET_PT_BOTH(position, byte) (set_point_both (position, byte))
223 #define TEMP_SET_PT_BOTH(position, byte) \
224 (temp_set_point_both (current_buffer, (position), (byte)))
226 #define BUF_TEMP_SET_PT(buffer, position) \
227 (temp_set_point ((buffer), (position)))
229 extern void set_point (EMACS_INT);
230 extern void temp_set_point (struct buffer *, EMACS_INT);
231 extern void set_point_both (EMACS_INT, EMACS_INT);
232 extern void temp_set_point_both (struct buffer *,
233 EMACS_INT, EMACS_INT);
234 extern void enlarge_buffer_text (struct buffer *, EMACS_INT);
237 /* Macros for setting the BEGV, ZV or PT of a given buffer.
239 SET_BUF_PT* seet to be redundant. Get rid of them?
241 The ..._BOTH macros take both a charpos and a bytepos,
242 which must correspond to each other.
244 The macros without ..._BOTH take just a charpos,
245 and compute the bytepos from it. */
247 #define SET_BUF_BEGV(buf, charpos) \
248 ((buf)->begv_byte = buf_charpos_to_bytepos ((buf), (charpos)), \
249 (buf)->begv = (charpos))
251 #define SET_BUF_ZV(buf, charpos) \
252 ((buf)->zv_byte = buf_charpos_to_bytepos ((buf), (charpos)), \
253 (buf)->zv = (charpos))
255 #define SET_BUF_BEGV_BOTH(buf, charpos, byte) \
256 ((buf)->begv = (charpos), \
257 (buf)->begv_byte = (byte))
259 #define SET_BUF_ZV_BOTH(buf, charpos, byte) \
260 ((buf)->zv = (charpos), \
261 (buf)->zv_byte = (byte))
263 #define SET_BUF_PT_BOTH(buf, charpos, byte) \
264 ((buf)->pt = (charpos), \
265 (buf)->pt_byte = (byte))
267 /* Macros to access a character or byte in the current buffer,
268 or convert between a byte position and an address.
269 These macros do not check that the position is in range. */
271 /* Access a Lisp position value in POS,
272 and store the charpos in CHARPOS and the bytepos in BYTEPOS. */
274 #define DECODE_POSITION(charpos, bytepos, pos) \
275 do \
277 Lisp_Object __pos = (pos); \
278 if (NUMBERP (__pos)) \
280 charpos = __pos; \
281 bytepos = buf_charpos_to_bytepos (current_buffer, __pos); \
283 else if (MARKERP (__pos)) \
285 charpos = marker_position (__pos); \
286 bytepos = marker_byte_position (__pos); \
288 else \
289 wrong_type_argument (Qinteger_or_marker_p, __pos); \
291 while (0)
293 /* Return the address of byte position N in current buffer. */
295 #define BYTE_POS_ADDR(n) \
296 (((n) >= GPT_BYTE ? GAP_SIZE : 0) + (n) + BEG_ADDR - BEG_BYTE)
298 /* Return the address of char position N. */
300 #define CHAR_POS_ADDR(n) \
301 (((n) >= GPT ? GAP_SIZE : 0) \
302 + buf_charpos_to_bytepos (current_buffer, n) \
303 + BEG_ADDR - BEG_BYTE)
305 /* Convert a character position to a byte position. */
307 #define CHAR_TO_BYTE(charpos) \
308 (buf_charpos_to_bytepos (current_buffer, charpos))
310 /* Convert a byte position to a character position. */
312 #define BYTE_TO_CHAR(bytepos) \
313 (buf_bytepos_to_charpos (current_buffer, bytepos))
315 /* Convert PTR, the address of a byte in the buffer, into a byte position. */
317 #define PTR_BYTE_POS(ptr) \
318 ((ptr) - (current_buffer)->text->beg \
319 - (ptr - (current_buffer)->text->beg <= (unsigned) (GPT_BYTE - BEG_BYTE) ? 0 : GAP_SIZE) \
320 + BEG_BYTE)
322 /* Return character at byte position POS. */
324 #define FETCH_CHAR(pos) \
325 (!NILP (current_buffer->enable_multibyte_characters) \
326 ? FETCH_MULTIBYTE_CHAR ((pos)) \
327 : FETCH_BYTE ((pos)))
329 /* Return the byte at byte position N. */
331 #define FETCH_BYTE(n) *(BYTE_POS_ADDR ((n)))
333 /* Variables used locally in FETCH_MULTIBYTE_CHAR. */
334 extern unsigned char *_fetch_multibyte_char_p;
336 /* Return character code of multi-byte form at byte position POS. If POS
337 doesn't point the head of valid multi-byte form, only the byte at
338 POS is returned. No range checking. */
340 #define FETCH_MULTIBYTE_CHAR(pos) \
341 (_fetch_multibyte_char_p = (((pos) >= GPT_BYTE ? GAP_SIZE : 0) \
342 + (pos) + BEG_ADDR - BEG_BYTE), \
343 STRING_CHAR (_fetch_multibyte_char_p))
345 /* Return character at byte position POS. If the current buffer is unibyte
346 and the character is not ASCII, make the returning character
347 multibyte. */
349 #define FETCH_CHAR_AS_MULTIBYTE(pos) \
350 (!NILP (current_buffer->enable_multibyte_characters) \
351 ? FETCH_MULTIBYTE_CHAR ((pos)) \
352 : UNIBYTE_TO_CHAR (FETCH_BYTE ((pos))))
355 /* Macros for accessing a character or byte,
356 or converting between byte positions and addresses,
357 in a specified buffer. */
359 /* Return the address of character at byte position POS in buffer BUF.
360 Note that both arguments can be computed more than once. */
362 #define BUF_BYTE_ADDRESS(buf, pos) \
363 ((buf)->text->beg + (pos) - BEG_BYTE \
364 + ((pos) >= (buf)->text->gpt_byte ? (buf)->text->gap_size : 0))
366 /* Return the address of character at char position POS in buffer BUF.
367 Note that both arguments can be computed more than once. */
369 #define BUF_CHAR_ADDRESS(buf, pos) \
370 ((buf)->text->beg + buf_charpos_to_bytepos ((buf), (pos)) - BEG_BYTE \
371 + ((pos) >= (buf)->text->gpt ? (buf)->text->gap_size : 0))
373 /* Convert PTR, the address of a char in buffer BUF,
374 into a character position. */
376 #define BUF_PTR_BYTE_POS(buf, ptr) \
377 ((ptr) - (buf)->text->beg \
378 - (ptr - (buf)->text->beg <= (unsigned) (BUF_GPT_BYTE ((buf)) - BEG_BYTE)\
379 ? 0 : BUF_GAP_SIZE ((buf))) \
380 + BEG_BYTE)
382 /* Return the character at byte position POS in buffer BUF. */
384 #define BUF_FETCH_CHAR(buf, pos) \
385 (!NILP (buf->enable_multibyte_characters) \
386 ? BUF_FETCH_MULTIBYTE_CHAR ((buf), (pos)) \
387 : BUF_FETCH_BYTE ((buf), (pos)))
389 /* Return the byte at byte position N in buffer BUF. */
391 #define BUF_FETCH_BYTE(buf, n) \
392 *(BUF_BYTE_ADDRESS ((buf), (n)))
394 /* Return character code of multi-byte form at byte position POS in BUF.
395 If POS doesn't point the head of valid multi-byte form, only the byte at
396 POS is returned. No range checking. */
398 #define BUF_FETCH_MULTIBYTE_CHAR(buf, pos) \
399 (_fetch_multibyte_char_p \
400 = (((pos) >= BUF_GPT_BYTE (buf) ? BUF_GAP_SIZE (buf) : 0) \
401 + (pos) + BUF_BEG_ADDR (buf) - BEG_BYTE), \
402 STRING_CHAR (_fetch_multibyte_char_p))
404 /* Define the actual buffer data structures. */
406 /* This data structure describes the actual text contents of a buffer.
407 It is shared between indirect buffers and their base buffer. */
409 struct buffer_text
411 /* Actual address of buffer contents. If REL_ALLOC is defined,
412 this address might change when blocks are relocated which can
413 e.g. happen when malloc is called. So, don't pass a pointer
414 into a buffer's text to functions that malloc. */
415 unsigned char *beg;
417 EMACS_INT gpt; /* Char pos of gap in buffer. */
418 EMACS_INT z; /* Char pos of end of buffer. */
419 EMACS_INT gpt_byte; /* Byte pos of gap in buffer. */
420 EMACS_INT z_byte; /* Byte pos of end of buffer. */
421 EMACS_INT gap_size; /* Size of buffer's gap. */
422 int modiff; /* This counts buffer-modification events
423 for this buffer. It is incremented for
424 each such event, and never otherwise
425 changed. */
426 int chars_modiff; /* This is modified with character change
427 events for this buffer. It is set to
428 modiff for each such event, and never
429 otherwise changed. */
430 int save_modiff; /* Previous value of modiff, as of last
431 time buffer visited or saved a file. */
433 int overlay_modiff; /* Counts modifications to overlays. */
435 /* Minimum value of GPT - BEG since last redisplay that finished. */
436 EMACS_INT beg_unchanged;
438 /* Minimum value of Z - GPT since last redisplay that finished. */
439 EMACS_INT end_unchanged;
441 /* MODIFF as of last redisplay that finished; if it matches MODIFF,
442 beg_unchanged and end_unchanged contain no useful information. */
443 int unchanged_modified;
445 /* BUF_OVERLAY_MODIFF of current buffer, as of last redisplay that
446 finished; if it matches BUF_OVERLAY_MODIFF, beg_unchanged and
447 end_unchanged contain no useful information. */
448 int overlay_unchanged_modified;
450 /* Properties of this buffer's text. */
451 INTERVAL intervals;
453 /* The markers that refer to this buffer.
454 This is actually a single marker ---
455 successive elements in its marker `chain'
456 are the other markers referring to this buffer.
457 This is a singly linked unordered list, which means that it's
458 very cheap to add a marker to the list and it's also very cheap
459 to move a marker within a buffer. */
460 struct Lisp_Marker *markers;
462 /* Usually 0. Temporarily set to 1 in decode_coding_gap to
463 prevent Fgarbage_collect from shrinking the gap and losing
464 not-yet-decoded bytes. */
465 int inhibit_shrinking;
468 /* This is the structure that the buffer Lisp object points to. */
470 struct buffer
472 /* Everything before the `name' slot must be of a non-Lisp_Object type,
473 and every slot after `name' must be a Lisp_Object.
475 Check out mark_buffer (alloc.c) to see why. */
477 EMACS_UINT size;
479 /* Next buffer, in chain of all buffers including killed buffers.
480 This chain is used only for garbage collection, in order to
481 collect killed buffers properly.
482 Note that vectors and most pseudovectors are all on one chain,
483 but buffers are on a separate chain of their own. */
484 struct buffer *next;
486 /* This structure holds the coordinates of the buffer contents
487 in ordinary buffers. In indirect buffers, this is not used. */
488 struct buffer_text own_text;
490 /* This points to the `struct buffer_text' that used for this buffer.
491 In an ordinary buffer, this is the own_text field above.
492 In an indirect buffer, this is the own_text field of another buffer. */
493 struct buffer_text *text;
495 /* Char position of point in buffer. */
496 EMACS_INT pt;
497 /* Byte position of point in buffer. */
498 EMACS_INT pt_byte;
499 /* Char position of beginning of accessible range. */
500 EMACS_INT begv;
501 /* Byte position of beginning of accessible range. */
502 EMACS_INT begv_byte;
503 /* Char position of end of accessible range. */
504 EMACS_INT zv;
505 /* Byte position of end of accessible range. */
506 EMACS_INT zv_byte;
508 /* In an indirect buffer, this points to the base buffer.
509 In an ordinary buffer, it is 0. */
510 struct buffer *base_buffer;
512 /* A non-zero value in slot IDX means that per-buffer variable
513 with index IDX has a local value in this buffer. The index IDX
514 for a buffer-local variable is stored in that variable's slot
515 in buffer_local_flags as a Lisp integer. If the index is -1,
516 this means the variable is always local in all buffers. */
517 #define MAX_PER_BUFFER_VARS 50
518 char local_flags[MAX_PER_BUFFER_VARS];
520 /* Set to the modtime of the visited file when read or written.
521 -1 means visited file was nonexistent.
522 0 means visited file modtime unknown; in no case complain
523 about any mismatch on next save attempt. */
524 int modtime;
525 /* Size of the file when modtime was set. This is used to detect the
526 case where the file grew while we were reading it, so the modtime
527 is still the same (since it's rounded up to seconds) but we're actually
528 not up-to-date. -1 means the size is unknown. Only meaningful if
529 modtime is actually set. */
530 EMACS_INT modtime_size;
531 /* The value of text->modiff at the last auto-save. */
532 int auto_save_modified;
533 /* The value of text->modiff at the last display error.
534 Redisplay of this buffer is inhibited until it changes again. */
535 int display_error_modiff;
536 /* The time at which we detected a failure to auto-save,
537 Or -1 if we didn't have a failure. */
538 int auto_save_failure_time;
539 /* Position in buffer at which display started
540 the last time this buffer was displayed. */
541 EMACS_INT last_window_start;
543 /* Set nonzero whenever the narrowing is changed in this buffer. */
544 int clip_changed;
546 /* If the long line scan cache is enabled (i.e. the buffer-local
547 variable cache-long-line-scans is non-nil), newline_cache
548 points to the newline cache, and width_run_cache points to the
549 width run cache.
551 The newline cache records which stretches of the buffer are
552 known *not* to contain newlines, so that they can be skipped
553 quickly when we search for newlines.
555 The width run cache records which stretches of the buffer are
556 known to contain characters whose widths are all the same. If
557 the width run cache maps a character to a value > 0, that value is
558 the character's width; if it maps a character to zero, we don't
559 know what its width is. This allows compute_motion to process
560 such regions very quickly, using algebra instead of inspecting
561 each character. See also width_table, below. */
562 struct region_cache *newline_cache;
563 struct region_cache *width_run_cache;
565 /* Non-zero means don't use redisplay optimizations for
566 displaying this buffer. */
567 unsigned prevent_redisplay_optimizations_p : 1;
569 /* List of overlays that end at or before the current center,
570 in order of end-position. */
571 struct Lisp_Overlay *overlays_before;
573 /* List of overlays that end after the current center,
574 in order of start-position. */
575 struct Lisp_Overlay *overlays_after;
577 /* Position where the overlay lists are centered. */
578 EMACS_INT overlay_center;
580 /* Everything from here down must be a Lisp_Object. */
581 /* buffer-local Lisp variables start at `undo_list',
582 tho only the ones from `name' on are GC'd normally. */
584 /* Changes in the buffer are recorded here for undo.
585 t means don't record anything.
586 This information belongs to the base buffer of an indirect buffer,
587 But we can't store it in the struct buffer_text
588 because local variables have to be right in the struct buffer.
589 So we copy it around in set_buffer_internal.
590 This comes before `name' because it is marked in a special way. */
591 Lisp_Object undo_list;
593 /* The name of this buffer. */
594 Lisp_Object name;
596 /* The name of the file visited in this buffer, or nil. */
597 Lisp_Object filename;
598 /* Dir for expanding relative file names. */
599 Lisp_Object directory;
600 /* True if this buffer has been backed up (if you write to the
601 visited file and it hasn't been backed up, then a backup will
602 be made). */
603 /* This isn't really used by the C code, so could be deleted. */
604 Lisp_Object backed_up;
605 /* Length of file when last read or saved.
606 -1 means auto saving turned off because buffer shrank a lot.
607 -2 means don't turn off auto saving if buffer shrinks.
608 (That value is used with buffer-swap-text.)
609 This is not in the struct buffer_text
610 because it's not used in indirect buffers at all. */
611 Lisp_Object save_length;
612 /* File name used for auto-saving this buffer.
613 This is not in the struct buffer_text
614 because it's not used in indirect buffers at all. */
615 Lisp_Object auto_save_file_name;
617 /* Non-nil if buffer read-only. */
618 Lisp_Object read_only;
619 /* "The mark". This is a marker which may
620 point into this buffer or may point nowhere. */
621 Lisp_Object mark;
623 /* Alist of elements (SYMBOL . VALUE-IN-THIS-BUFFER) for all
624 per-buffer variables of this buffer. For locally unbound
625 symbols, just the symbol appears as the element. */
626 Lisp_Object local_var_alist;
628 /* Symbol naming major mode (eg, lisp-mode). */
629 Lisp_Object major_mode;
630 /* Pretty name of major mode (eg, "Lisp"). */
631 Lisp_Object mode_name;
632 /* Mode line element that controls format of mode line. */
633 Lisp_Object mode_line_format;
635 /* Analogous to mode_line_format for the line displayed at the top
636 of windows. Nil means don't display that line. */
637 Lisp_Object header_line_format;
639 /* Keys that are bound local to this buffer. */
640 Lisp_Object keymap;
641 /* This buffer's local abbrev table. */
642 Lisp_Object abbrev_table;
643 /* This buffer's syntax table. */
644 Lisp_Object syntax_table;
645 /* This buffer's category table. */
646 Lisp_Object category_table;
648 /* Values of several buffer-local variables. */
649 /* tab-width is buffer-local so that redisplay can find it
650 in buffers that are not current. */
651 Lisp_Object case_fold_search;
652 Lisp_Object tab_width;
653 Lisp_Object fill_column;
654 Lisp_Object left_margin;
655 /* Function to call when insert space past fill column. */
656 Lisp_Object auto_fill_function;
657 /* nil: text, t: binary.
658 This value is meaningful only on certain operating systems. */
659 /* Actually, we don't need this flag any more because end-of-line
660 is handled correctly according to the buffer-file-coding-system
661 of the buffer. Just keeping it for backward compatibility. */
662 Lisp_Object buffer_file_type;
664 /* Case table for case-conversion in this buffer.
665 This char-table maps each char into its lower-case version. */
666 Lisp_Object downcase_table;
667 /* Char-table mapping each char to its upper-case version. */
668 Lisp_Object upcase_table;
669 /* Char-table for conversion for case-folding search. */
670 Lisp_Object case_canon_table;
671 /* Char-table of equivalences for case-folding search. */
672 Lisp_Object case_eqv_table;
674 /* Non-nil means do not display continuation lines. */
675 Lisp_Object truncate_lines;
676 /* Non-nil means to use word wrapping when displaying continuation lines. */
677 Lisp_Object word_wrap;
678 /* Non-nil means display ctl chars with uparrow. */
679 Lisp_Object ctl_arrow;
680 /* Non-nil means reorder bidirectional text for display in the
681 visual order. */
682 Lisp_Object bidi_display_reordering;
683 /* If non-nil, specifies which direction of text to force in all the
684 paragraphs of the buffer. Nil means determine paragraph
685 direction dynamically for each paragraph. */
686 Lisp_Object bidi_paragraph_direction;
687 /* Non-nil means do selective display;
688 see doc string in syms_of_buffer (buffer.c) for details. */
689 Lisp_Object selective_display;
690 #ifndef old
691 /* Non-nil means show ... at end of line followed by invisible lines. */
692 Lisp_Object selective_display_ellipses;
693 #endif
694 /* Alist of (FUNCTION . STRING) for each minor mode enabled in buffer. */
695 Lisp_Object minor_modes;
696 /* t if "self-insertion" should overwrite; `binary' if it should also
697 overwrite newlines and tabs - for editing executables and the like. */
698 Lisp_Object overwrite_mode;
699 /* non-nil means abbrev mode is on. Expand abbrevs automatically. */
700 Lisp_Object abbrev_mode;
701 /* Display table to use for text in this buffer. */
702 Lisp_Object display_table;
703 /* t means the mark and region are currently active. */
704 Lisp_Object mark_active;
706 /* Non-nil means the buffer contents are regarded as multi-byte
707 form of characters, not a binary code. */
708 Lisp_Object enable_multibyte_characters;
710 /* Coding system to be used for encoding the buffer contents on
711 saving. */
712 Lisp_Object buffer_file_coding_system;
714 /* List of symbols naming the file format used for visited file. */
715 Lisp_Object file_format;
717 /* List of symbols naming the file format used for auto-save file. */
718 Lisp_Object auto_save_file_format;
720 /* True if the newline position cache and width run cache are
721 enabled. See search.c and indent.c. */
722 Lisp_Object cache_long_line_scans;
724 /* If the width run cache is enabled, this table contains the
725 character widths width_run_cache (see above) assumes. When we
726 do a thorough redisplay, we compare this against the buffer's
727 current display table to see whether the display table has
728 affected the widths of any characters. If it has, we
729 invalidate the width run cache, and re-initialize width_table. */
730 Lisp_Object width_table;
732 /* In an indirect buffer, or a buffer that is the base of an
733 indirect buffer, this holds a marker that records
734 PT for this buffer when the buffer is not current. */
735 Lisp_Object pt_marker;
737 /* In an indirect buffer, or a buffer that is the base of an
738 indirect buffer, this holds a marker that records
739 BEGV for this buffer when the buffer is not current. */
740 Lisp_Object begv_marker;
742 /* In an indirect buffer, or a buffer that is the base of an
743 indirect buffer, this holds a marker that records
744 ZV for this buffer when the buffer is not current. */
745 Lisp_Object zv_marker;
747 /* This holds the point value before the last scroll operation.
748 Explicitly setting point sets this to nil. */
749 Lisp_Object point_before_scroll;
751 /* Truename of the visited file, or nil. */
752 Lisp_Object file_truename;
754 /* Invisibility spec of this buffer.
755 t => any non-nil `invisible' property means invisible.
756 A list => `invisible' property means invisible
757 if it is memq in that list. */
758 Lisp_Object invisibility_spec;
760 /* This is the last window that was selected with this buffer in it,
761 or nil if that window no longer displays this buffer. */
762 Lisp_Object last_selected_window;
764 /* Incremented each time the buffer is displayed in a window. */
765 Lisp_Object display_count;
767 /* Widths of left and right marginal areas for windows displaying
768 this buffer. */
769 Lisp_Object left_margin_cols, right_margin_cols;
771 /* Widths of left and right fringe areas for windows displaying
772 this buffer. */
773 Lisp_Object left_fringe_width, right_fringe_width;
775 /* Non-nil means fringes are drawn outside display margins;
776 othersize draw them between margin areas and text. */
777 Lisp_Object fringes_outside_margins;
779 /* Width and type of scroll bar areas for windows displaying
780 this buffer. */
781 Lisp_Object scroll_bar_width, vertical_scroll_bar_type;
783 /* Non-nil means indicate lines not displaying text (in a style
784 like vi). */
785 Lisp_Object indicate_empty_lines;
787 /* Non-nil means indicate buffer boundaries and scrolling. */
788 Lisp_Object indicate_buffer_boundaries;
790 /* Logical to physical fringe bitmap mappings. */
791 Lisp_Object fringe_indicator_alist;
793 /* Logical to physical cursor bitmap mappings. */
794 Lisp_Object fringe_cursor_alist;
796 /* Time stamp updated each time this buffer is displayed in a window. */
797 Lisp_Object display_time;
799 /* If scrolling the display because point is below the bottom of a
800 window showing this buffer, try to choose a window start so
801 that point ends up this number of lines from the top of the
802 window. Nil means that scrolling method isn't used. */
803 Lisp_Object scroll_up_aggressively;
805 /* If scrolling the display because point is above the top of a
806 window showing this buffer, try to choose a window start so
807 that point ends up this number of lines from the bottom of the
808 window. Nil means that scrolling method isn't used. */
809 Lisp_Object scroll_down_aggressively;
811 /* Desired cursor type in this buffer. See the doc string of
812 per-buffer variable `cursor-type'. */
813 Lisp_Object cursor_type;
815 /* An integer > 0 means put that number of pixels below text lines
816 in the display of this buffer. */
817 Lisp_Object extra_line_spacing;
819 /* *Cursor type to display in non-selected windows.
820 t means to use hollow box cursor.
821 See `cursor-type' for other values. */
822 Lisp_Object cursor_in_non_selected_windows;
826 /* This points to the current buffer. */
828 extern struct buffer *current_buffer;
830 /* This structure holds the default values of the buffer-local variables
831 that have special slots in each buffer.
832 The default value occupies the same slot in this structure
833 as an individual buffer's value occupies in that buffer.
834 Setting the default value also goes through the alist of buffers
835 and stores into each buffer that does not say it has a local value. */
837 extern struct buffer buffer_defaults;
839 /* This structure marks which slots in a buffer have corresponding
840 default values in buffer_defaults.
841 Each such slot has a nonzero value in this structure.
842 The value has only one nonzero bit.
844 When a buffer has its own local value for a slot,
845 the entry for that slot (found in the same slot in this structure)
846 is turned on in the buffer's local_flags array.
848 If a slot in this structure is zero, then even though there may
849 be a Lisp-level local variable for the slot, it has no default value,
850 and the corresponding slot in buffer_defaults is not used. */
853 extern struct buffer buffer_local_flags;
855 /* For each buffer slot, this points to the Lisp symbol name
856 for that slot in the current buffer. It is 0 for slots
857 that don't have such names. */
859 extern struct buffer buffer_local_symbols;
861 extern void delete_all_overlays (struct buffer *);
862 extern void reset_buffer (struct buffer *);
863 extern void evaporate_overlays (EMACS_INT);
864 extern int overlays_at (EMACS_INT pos, int extend, Lisp_Object **vec_ptr,
865 int *len_ptr, EMACS_INT *next_ptr,
866 EMACS_INT *prev_ptr, int change_req);
867 extern int sort_overlays (Lisp_Object *, int, struct window *);
868 extern void recenter_overlay_lists (struct buffer *, EMACS_INT);
869 extern EMACS_INT overlay_strings (EMACS_INT, struct window *, unsigned char **);
870 extern void validate_region (Lisp_Object *, Lisp_Object *);
871 extern void set_buffer_internal (struct buffer *);
872 extern void set_buffer_internal_1 (struct buffer *);
873 extern void set_buffer_temp (struct buffer *);
874 extern void record_buffer (Lisp_Object);
875 extern void buffer_slot_type_mismatch (Lisp_Object, int) NO_RETURN;
876 extern void fix_overlays_before (struct buffer *, EMACS_INT, EMACS_INT);
877 extern void mmap_set_vars (int);
879 /* Get overlays at POSN into array OVERLAYS with NOVERLAYS elements.
880 If NEXTP is non-NULL, return next overlay there.
881 See overlay_at arg CHANGE_REQ for meaning of CHRQ arg. */
883 #define GET_OVERLAYS_AT(posn, overlays, noverlays, nextp, chrq) \
884 do { \
885 int maxlen = 40; \
886 overlays = (Lisp_Object *) alloca (maxlen * sizeof (Lisp_Object)); \
887 noverlays = overlays_at (posn, 0, &overlays, &maxlen, \
888 nextp, NULL, chrq); \
889 if (noverlays > maxlen) \
891 maxlen = noverlays; \
892 overlays = (Lisp_Object *) alloca (maxlen * sizeof (Lisp_Object)); \
893 noverlays = overlays_at (posn, 0, &overlays, &maxlen, \
894 nextp, NULL, chrq); \
896 } while (0)
898 EXFUN (Fbuffer_live_p, 1);
899 EXFUN (Fbuffer_name, 1);
900 EXFUN (Fnext_overlay_change, 1);
901 EXFUN (Fdelete_overlay, 1);
902 EXFUN (Fbuffer_local_value, 2);
904 /* Functions to call before and after each text change. */
905 extern Lisp_Object Vbefore_change_functions;
906 extern Lisp_Object Vafter_change_functions;
907 extern Lisp_Object Vfirst_change_hook;
908 extern Lisp_Object Qbefore_change_functions;
909 extern Lisp_Object Qafter_change_functions;
910 extern Lisp_Object Qfirst_change_hook;
912 /* If nonzero, all modification hooks are suppressed. */
913 extern int inhibit_modification_hooks;
915 extern Lisp_Object Vdeactivate_mark;
916 extern Lisp_Object Vtransient_mark_mode;
918 /* Overlays */
920 /* 1 if the OV is an overlay object. */
922 #define OVERLAY_VALID(OV) (OVERLAYP (OV))
924 /* Return the marker that stands for where OV starts in the buffer. */
926 #define OVERLAY_START(OV) (XOVERLAY (OV)->start)
928 /* Return the marker that stands for where OV ends in the buffer. */
930 #define OVERLAY_END(OV) (XOVERLAY (OV)->end)
932 /* Return the plist of overlay OV. */
934 #define OVERLAY_PLIST(OV) XOVERLAY ((OV))->plist
936 /* Return the actual buffer position for the marker P.
937 We assume you know which buffer it's pointing into. */
939 #define OVERLAY_POSITION(P) \
940 (MARKERP (P) ? marker_position (P) : (abort (), 0))
943 /***********************************************************************
944 Buffer-local Variables
945 ***********************************************************************/
947 /* Number of per-buffer variables used. */
949 extern int last_per_buffer_idx;
951 /* Return the offset in bytes of member VAR of struct buffer
952 from the start of a buffer structure. */
954 #define PER_BUFFER_VAR_OFFSET(VAR) \
955 offsetof (struct buffer, VAR)
957 /* Return the index of buffer-local variable VAR. Each per-buffer
958 variable has an index > 0 associated with it, except when it always
959 has buffer-local values, in which case the index is -1. If this is
960 0, this is a bug and means that the slot of VAR in
961 buffer_local_flags wasn't intiialized. */
963 #define PER_BUFFER_VAR_IDX(VAR) \
964 PER_BUFFER_IDX (PER_BUFFER_VAR_OFFSET (VAR))
966 /* Value is non-zero if the variable with index IDX has a local value
967 in buffer B. */
969 #define PER_BUFFER_VALUE_P(B, IDX) \
970 (((IDX) < 0 || IDX >= last_per_buffer_idx) \
971 ? (abort (), 0) \
972 : ((B)->local_flags[IDX] != 0))
974 /* Set whether per-buffer variable with index IDX has a buffer-local
975 value in buffer B. VAL zero means it hasn't. */
977 #define SET_PER_BUFFER_VALUE_P(B, IDX, VAL) \
978 do { \
979 if ((IDX) < 0 || (IDX) >= last_per_buffer_idx) \
980 abort (); \
981 (B)->local_flags[IDX] = (VAL); \
982 } while (0)
984 /* Return the index value of the per-buffer variable at offset OFFSET
985 in the buffer structure.
987 If the slot OFFSET has a corresponding default value in
988 buffer_defaults, the index value is positive and has only one
989 nonzero bit. When a buffer has its own local value for a slot, the
990 bit for that slot (found in the same slot in this structure) is
991 turned on in the buffer's local_flags array.
993 If the index value is -1, even though there may be a
994 DEFVAR_PER_BUFFER for the slot, there is no default value for it;
995 and the corresponding slot in buffer_defaults is not used.
997 If the index value is -2, then there is no DEFVAR_PER_BUFFER for
998 the slot, but there is a default value which is copied into each
999 new buffer.
1001 If a slot in this structure corresponding to a DEFVAR_PER_BUFFER is
1002 zero, that is a bug */
1005 #define PER_BUFFER_IDX(OFFSET) \
1006 XINT (*(Lisp_Object *)((OFFSET) + (char *) &buffer_local_flags))
1008 /* Return the default value of the per-buffer variable at offset
1009 OFFSET in the buffer structure. */
1011 #define PER_BUFFER_DEFAULT(OFFSET) \
1012 (*(Lisp_Object *)((OFFSET) + (char *) &buffer_defaults))
1014 /* Return the buffer-local value of the per-buffer variable at offset
1015 OFFSET in the buffer structure. */
1017 #define PER_BUFFER_VALUE(BUFFER, OFFSET) \
1018 (*(Lisp_Object *)((OFFSET) + (char *) (BUFFER)))