src/buffer.h

   1 /* Header file for the buffer manipulation primitives.
   2    Copyright (C) 1985, 1986, 1993, 1994, 1995 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 #ifdef USE_TEXT_PROPERTIES
  23 #define SET_PT(position) (set_point ((position), current_buffer))
  24 #define TEMP_SET_PT(position) (temp_set_point ((position), current_buffer))
  25
  26 #define BUF_SET_PT(buffer, position) (set_point ((position), (buffer)))
  27 #define BUF_TEMP_SET_PT(buffer, position) (temp_set_point ((position), (buffer)))
  28
  29 #else  /* don't support text properties */
  30
  31 #define SET_PT(position) (current_buffer->pt = (position))
  32 #define TEMP_SET_PT(position) (current_buffer->pt = (position))
  33
  34 #define BUF_SET_PT(buffer, position) (buffer->pt = (position))
  35 #define BUF_TEMP_SET_PT(buffer, position) (buffer->pt = (position))
  36 #endif /* don't support text properties */
  37
  38 /* Character position of beginning of buffer.  */
  39 #define BEG (1)
  40
  41 /* Character position of beginning of accessible range of buffer.  */
  42 #define BEGV (current_buffer->begv)
  43
  44 /* Character position of point in buffer.  The "+ 0" makes this
  45    not an l-value, so you can't assign to it.  Use SET_PT instead.  */
  46 #define PT (current_buffer->pt + 0)
  47
  48 /* Character position of gap in buffer.  */
  49 #define GPT (current_buffer->text->gpt)
  50
  51 /* Character position of end of accessible range of buffer.  */
  52 #define ZV (current_buffer->zv)
  53
  54 /* Character position of end of buffer.  */
  55 #define Z (current_buffer->text->z)
  56
  57 /* Is the current buffer narrowed? */
  58 #define NARROWED        ((BEGV != BEG) || (ZV != Z))
  59
  60 /* Modification count.  */
  61 #define MODIFF (current_buffer->text->modiff)
  62
  63 /* Overlay modification count.  */
  64 #define OVERLAY_MODIFF (current_buffer->text->overlay_modiff)
  65
  66 /* Modification count as of last visit or save.  */
  67 #define SAVE_MODIFF (current_buffer->text->save_modiff)
  68
  69 /* Address of beginning of buffer.  */
  70 #define BEG_ADDR (current_buffer->text->beg)
  71
  72 /* Address of beginning of accessible range of buffer.  */
  73 #define BEGV_ADDR (&FETCH_CHAR (current_buffer->begv))
  74
  75 /* Address of point in buffer.  */
  76 #define PT_ADDR (&FETCH_CHAR (current_buffer->pt))
  77
  78 /* Address of beginning of gap in buffer.  */
  79 #define GPT_ADDR (current_buffer->text->beg + current_buffer->text->gpt - 1)
  80
  81 /* Address of end of gap in buffer.  */
  82 #define GAP_END_ADDR (current_buffer->text->beg + current_buffer->text->gpt + current_buffer->text->gap_size - 1)
  83
  84 /* Address of end of accessible range of buffer.  */
  85 #define ZV_ADDR (&FETCH_CHAR (current_buffer->zv))
  86
  87 /* Size of gap.  */
  88 #define GAP_SIZE (current_buffer->text->gap_size)
  89
  90 /* Now similar macros for a specified buffer.
  91    Note that many of these evaluate the buffer argument more than once.  */
  92
  93 /* Character position of beginning of buffer.  */
  94 #define BUF_BEG(buf) (1)
  95
  96 /* Character position of beginning of accessible range of buffer.  */
  97 #define BUF_BEGV(buf) ((buf)->begv)
  98
  99 /* Character position of point in buffer.  */
 100 #define BUF_PT(buf) ((buf)->pt)
 101
 102 /* Character position of gap in buffer.  */
 103 #define BUF_GPT(buf) ((buf)->text->gpt)
 104
 105 /* Character position of end of accessible range of buffer.  */
 106 #define BUF_ZV(buf) ((buf)->zv)
 107
 108 /* Character position of end of buffer.  */
 109 #define BUF_Z(buf) ((buf)->text->z)
 110
 111 /* Is this buffer narrowed? */
 112 #define BUF_NARROWED(buf) ((BUF_BEGV (buf) != BUF_BEG (buf)) \
 113                            || (BUF_ZV (buf) != BUF_Z (buf)))
 114
 115 /* Modification count.  */
 116 #define BUF_MODIFF(buf) ((buf)->text->modiff)
 117
 118 /* Modification count as of last visit or save.  */
 119 #define BUF_SAVE_MODIFF(buf) ((buf)->text->save_modiff)
 120
 121 /* Overlay modification count.  */
 122 #define BUF_OVERLAY_MODIFF(buf) ((buf)->text->overlay_modiff)
 123
 124 /* Interval tree of buffer.  */
 125 #define BUF_INTERVALS(buf) ((buf)->text->intervals)
 126
 127 /* Marker chain of buffer.  */
 128 #define BUF_MARKERS(buf) ((buf)->text->markers)
 129
 130 /* Address of beginning of buffer.  */
 131 #define BUF_BEG_ADDR(buf) ((buf)->text->beg)
 132
 133 /* Macro for setting the value of BUF_ZV (BUF) to VALUE,
 134    by varying the end of the accessible region.  */
 135 #define SET_BUF_ZV(buf, value) ((buf)->zv = (value))
 136 #define SET_BUF_PT(buf, value) ((buf)->pt = (value))
 137
 138 /* Size of gap.  */
 139 #define BUF_GAP_SIZE(buf) ((buf)->text->gap_size)
 140
 141 /* Return the address of character at position POS in buffer BUF.
 142    Note that both arguments can be computed more than once.  */
 143 #define BUF_CHAR_ADDRESS(buf, pos) \
 144 ((buf)->text->beg + (pos) - 1           \
 145  + ((pos) >= (buf)->text->gpt ? (buf)->text->gap_size : 0))
 146
 147 /* Convert the address of a char in the buffer into a character position.  */
 148 #define PTR_CHAR_POS(ptr) \
 149 ((ptr) - (current_buffer)->text->beg                                    \
 150  - (ptr - (current_buffer)->text->beg < (unsigned) GPT ? 0 : GAP_SIZE)  \
 151  + 1)
 152
 153 /* Convert the address of a char in the buffer into a character position.  */
 154 #define BUF_PTR_CHAR_POS(buf, ptr)                      \
 155 ((ptr) - (buf)->text->beg                               \
 156  - (ptr - (buf)->text->beg < (unsigned) BUF_GPT ((buf)) \
 157     ? 0 : BUF_GAP_SIZE ((buf)))                         \
 158  + 1)
 159 \f
 160 struct buffer_text
 161   {
 162     unsigned char *beg;         /* Actual address of buffer contents.  */
 163     int gpt;                    /* Index of gap in buffer.  */
 164     int z;                      /* Index of end of buffer.  */
 165     int gap_size;               /* Size of buffer's gap.  */
 166     int modiff;                 /* This counts buffer-modification events
 167                                    for this buffer.  It is incremented for
 168                                    each such event, and never otherwise
 169                                    changed.  */
 170     int save_modiff;            /* Previous value of modiff, as of last
 171                                    time buffer visited or saved a file.  */
 172
 173     int overlay_modiff;         /* Counts modifications to overlays.  */
 174
 175     /* Properties of this buffer's text -- conditionally compiled.  */
 176     DECLARE_INTERVALS
 177
 178     /* The markers that refer to this buffer.
 179        This is actually a single marker ---
 180        successive elements in its marker `chain'
 181        are the other markers referring to this buffer.  */
 182     Lisp_Object markers;
 183   };
 184
 185 struct buffer
 186   {
 187     /* Everything before the `name' slot must be of a non-Lisp_Object type,
 188        and every slot after `name' must be a Lisp_Object.
 189
 190        Check out mark_buffer (alloc.c) to see why.  */
 191
 192     EMACS_INT size;
 193
 194     /* Next buffer, in chain of all buffers including killed buffers.
 195        This chain is used only for garbage collection, in order to
 196        collect killed buffers properly.
 197        Note that vectors and most pseudovectors are all on one chain,
 198        but buffers are on a separate chain of their own.  */
 199     struct buffer *next;
 200
 201     /* This structure holds the coordinates of the buffer contents
 202        in ordinary buffers.  In indirect buffers, this is not used.  */
 203     struct buffer_text own_text;
 204
 205     /* This points to the `struct buffer_text' that used for this buffer.
 206        In an ordinary buffer, this is the own_text field above.
 207        In an indirect buffer, this is the own_text field of another buffer.  */
 208     struct buffer_text *text;
 209
 210     /* Position of point in buffer.  */
 211     int pt;
 212     /* Index of beginning of accessible range.  */
 213     int begv;
 214     /* Index of end of accessible range.  */
 215     int zv;
 216
 217     /* In an indirect buffer, this points to the base buffer.
 218        In an ordinary buffer, it is 0.  */
 219     struct buffer *base_buffer;
 220
 221     /* Flags saying which DEFVAR_PER_BUFFER variables
 222        are local to this buffer.  */
 223     int local_var_flags;
 224     /* Set to the modtime of the visited file when read or written.
 225        -1 means visited file was nonexistent.
 226        0 means visited file modtime unknown; in no case complain
 227        about any mismatch on next save attempt.  */
 228     int modtime;
 229     /* the value of text->modiff at the last auto-save.  */
 230     int auto_save_modified;
 231     /* The time at which we detected a failure to auto-save,
 232        Or -1 if we didn't have a failure.  */
 233     int auto_save_failure_time;
 234     /* Position in buffer at which display started
 235        the last time this buffer was displayed.  */
 236     int last_window_start;
 237
 238     /* Set nonzero whenever the narrowing is changed in this buffer.  */
 239     int clip_changed;
 240
 241     /* If the long line scan cache is enabled (i.e. the buffer-local
 242        variable cache-long-line-scans is non-nil), newline_cache
 243        points to the newline cache, and width_run_cache points to the
 244        width run cache.
 245
 246        The newline cache records which stretches of the buffer are
 247        known *not* to contain newlines, so that they can be skipped
 248        quickly when we search for newlines.
 249
 250        The width run cache records which stretches of the buffer are
 251        known to contain characters whose widths are all the same.  If
 252        the width run cache maps a character to a value > 0, that value is
 253        the character's width; if it maps a character to zero, we don't
 254        know what its width is.  This allows compute_motion to process
 255        such regions very quickly, using algebra instead of inspecting
 256        each character.   See also width_table, below.  */
 257     struct region_cache *newline_cache;
 258     struct region_cache *width_run_cache;
 259
 260     /* Everything from here down must be a Lisp_Object */
 261
 262
 263     /* The name of this buffer.  */
 264     Lisp_Object name;
 265     /* The name of the file visited in this buffer, or nil.  */
 266     Lisp_Object filename;
 267     /* Dir for expanding relative file names.  */
 268     Lisp_Object directory;
 269     /* True iff this buffer has been backed up (if you write to the
 270        visited file and it hasn't been backed up, then a backup will
 271        be made).  */
 272     /* This isn't really used by the C code, so could be deleted.  */
 273     Lisp_Object backed_up;
 274     /* Length of file when last read or saved.
 275        This is not in the  struct buffer_text
 276        because it's not used in indirect buffers at all.  */
 277     Lisp_Object save_length;
 278     /* File name used for auto-saving this buffer.
 279        This is not in the  struct buffer_text
 280        because it's not used in indirect buffers at all.  */
 281     Lisp_Object auto_save_file_name;
 282
 283     /* Non-nil if buffer read-only.  */
 284     Lisp_Object read_only;
 285     /* "The mark".  This is a marker which may
 286        point into this buffer or may point nowhere.  */
 287     Lisp_Object mark;
 288
 289     /* Alist of elements (SYMBOL . VALUE-IN-THIS-BUFFER)
 290        for all per-buffer variables of this buffer.  */
 291     Lisp_Object local_var_alist;
 292
 293     /* Symbol naming major mode (eg, lisp-mode).  */
 294     Lisp_Object major_mode;
 295     /* Pretty name of major mode (eg, "Lisp"). */
 296     Lisp_Object mode_name;
 297     /* Mode line element that controls format of mode line.  */
 298     Lisp_Object mode_line_format;
 299
 300     /* Keys that are bound local to this buffer.  */
 301     Lisp_Object keymap;
 302     /* This buffer's local abbrev table.  */
 303     Lisp_Object abbrev_table;
 304     /* This buffer's syntax table.  */
 305     Lisp_Object syntax_table;
 306
 307     /* Values of several buffer-local variables */
 308     /* tab-width is buffer-local so that redisplay can find it
 309        in buffers that are not current */
 310     Lisp_Object case_fold_search;
 311     Lisp_Object tab_width;
 312     Lisp_Object fill_column;
 313     Lisp_Object left_margin;
 314     /* Function to call when insert space past fill column.  */
 315     Lisp_Object auto_fill_function;
 316     /* nil: text, t: binary.
 317        This value is meaningful only on certain operating systems.  */
 318     Lisp_Object buffer_file_type;
 319
 320     /* Case table for case-conversion in this buffer.
 321        This char-table maps each char into its lower-case version.  */
 322     Lisp_Object downcase_table;
 323     /* Char-table mapping each char to its upper-case version.  */
 324     Lisp_Object upcase_table;
 325     /* Char-table for conversion for case-folding search.  */
 326     Lisp_Object case_canon_table;
 327     /* Char-table of equivalences for case-folding search.  */
 328     Lisp_Object case_eqv_table;
 329
 330     /* Non-nil means do not display continuation lines.  */
 331     Lisp_Object truncate_lines;
 332     /* Non-nil means display ctl chars with uparrow.  */
 333     Lisp_Object ctl_arrow;
 334     /* Non-nil means do selective display;
 335        see doc string in syms_of_buffer (buffer.c) for details.  */
 336     Lisp_Object selective_display;
 337 #ifndef old
 338     /* Non-nil means show ... at end of line followed by invisible lines.  */
 339     Lisp_Object selective_display_ellipses;
 340 #endif
 341     /* Alist of (FUNCTION . STRING) for each minor mode enabled in buffer.  */
 342     Lisp_Object minor_modes;
 343     /* t if "self-insertion" should overwrite; `binary' if it should also
 344        overwrite newlines and tabs - for editing executables and the like.  */
 345     Lisp_Object overwrite_mode;
 346     /* non-nil means abbrev mode is on.  Expand abbrevs automatically.  */
 347     Lisp_Object abbrev_mode;
 348     /* Display table to use for text in this buffer.  */
 349     Lisp_Object display_table;
 350     /* t means the mark and region are currently active.  */
 351     Lisp_Object mark_active;
 352
 353     /* Changes in the buffer are recorded here for undo.
 354        t means don't record anything.
 355        This information belongs to the base buffer of an indirect buffer,
 356        But we can't store it in the  struct buffer_text
 357        because local variables have to be right in the  struct buffer.
 358        So we copy it around in set_buffer_internal.  */
 359     Lisp_Object undo_list;
 360
 361     /* List of overlays that end at or before the current center,
 362        in order of end-position.  */
 363     Lisp_Object overlays_before;
 364
 365     /* List of overlays that end after  the current center,
 366        in order of start-position.  */
 367     Lisp_Object overlays_after;
 368
 369     /* Position where the overlay lists are centered.  */
 370     Lisp_Object overlay_center;
 371
 372     /* Lisp of symbols naming the file format used for visited file. */
 373     Lisp_Object file_format;
 374
 375     /* True if the newline position cache and width run cache are
 376        enabled.  See search.c and indent.c.  */
 377     Lisp_Object cache_long_line_scans;
 378
 379     /* If the width run cache is enabled, this table contains the
 380        character widths width_run_cache (see above) assumes.  When we
 381        do a thorough redisplay, we compare this against the buffer's
 382        current display table to see whether the display table has
 383        affected the widths of any characters.  If it has, we
 384        invalidate the width run cache, and re-initialize width_table.  */
 385     Lisp_Object width_table;
 386
 387     /* In an indirect buffer, or a buffer that is the base of an
 388        indirect buffer, this holds a marker that records
 389        PT for this buffer when the buffer is not current.  */
 390     Lisp_Object pt_marker;
 391
 392     /* In an indirect buffer, or a buffer that is the base of an
 393        indirect buffer, this holds a marker that records
 394        BEGV for this buffer when the buffer is not current.  */
 395     Lisp_Object begv_marker;
 396
 397     /* In an indirect buffer, or a buffer that is the base of an
 398        indirect buffer, this holds a marker that records
 399        ZV for this buffer when the buffer is not current.  */
 400     Lisp_Object zv_marker;
 401
 402     /* This holds the point value before the last scroll operation.
 403        Explicitly setting point sets this to nil.  */
 404     Lisp_Object point_before_scroll;
 405
 406     /* Truename of the visited file, or nil.  */
 407     Lisp_Object file_truename;
 408
 409     /* Invisibility spec of this buffer.
 410        t => any non-nil `invisible' property means invisible.
 411        A list => `invisible' property means invisible
 412                  if it is memq in that list.  */
 413     Lisp_Object invisibility_spec;
 414
 415     /* This is the last window that was selected with this buffer in it,
 416        or nil if that window no longer displays this buffer.  */
 417     Lisp_Object last_selected_window;
 418
 419     /* These are so we don't have to recompile everything
 420        the next few times we add a new slot.  */
 421     Lisp_Object extra2, extra3;
 422   };
 423 \f
 424 /* This points to the current buffer.  */
 425
 426 extern struct buffer *current_buffer;
 427
 428 /* This structure holds the default values of the buffer-local variables
 429    that have special slots in each buffer.
 430    The default value occupies the same slot in this structure
 431    as an individual buffer's value occupies in that buffer.
 432    Setting the default value also goes through the alist of buffers
 433    and stores into each buffer that does not say it has a local value.  */
 434
 435 extern struct buffer buffer_defaults;
 436
 437 /* This structure marks which slots in a buffer have corresponding
 438    default values in buffer_defaults.
 439    Each such slot has a nonzero value in this structure.
 440    The value has only one nonzero bit.
 441
 442    When a buffer has its own local value for a slot,
 443    the bit for that slot (found in the same slot in this structure)
 444    is turned on in the buffer's local_var_flags slot.
 445
 446    If a slot in this structure is zero, then even though there may
 447    be a Lisp-level local variable for the slot, it has no default value,
 448    and the corresponding slot in buffer_defaults is not used.  */
 449
 450 extern struct buffer buffer_local_flags;
 451
 452 /* For each buffer slot, this points to the Lisp symbol name
 453    for that slot in the current buffer.  It is 0 for slots
 454    that don't have such names.  */
 455
 456 extern struct buffer buffer_local_symbols;
 457
 458 /* This structure holds the required types for the values in the
 459    buffer-local slots.  If a slot contains Qnil, then the
 460    corresponding buffer slot may contain a value of any type.  If a
 461    slot contains an integer, then prospective values' tags must be
 462    equal to that integer.  When a tag does not match, the function
 463    buffer_slot_type_mismatch will signal an error.  The value Qnil may
 464    always be safely stored in any slot.  */
 465 extern struct buffer buffer_local_types;
 466 \f
 467 /* Point in the current buffer.  This is an obsolete alias
 468    and should be eliminated.  */
 469 #define point (current_buffer->pt + 0)
 470
 471 /* Return character at position n.  No range checking.  */
 472 #define FETCH_CHAR(n) *(((n)>= GPT ? GAP_SIZE : 0) + (n) + BEG_ADDR - 1)
 473
 474 /* BUFFER_CEILING_OF (resp. BUFFER_FLOOR_OF), when applied to n, return
 475    the max (resp. min) p such that
 476
 477    &FETCH_CHAR (p) - &FETCH_CHAR (n) == p - n       */
 478
 479 #define BUFFER_CEILING_OF(n) (((n) < GPT && GPT < ZV ? GPT : ZV) - 1)
 480 #define BUFFER_FLOOR_OF(n) (BEGV <= GPT && GPT <= (n) ? GPT : BEGV)
 481
 482 extern void reset_buffer ();
 483 extern void evaporate_overlays ();
 484
 485 extern Lisp_Object Fbuffer_name ();
 486 extern Lisp_Object Fget_file_buffer ();
 487 extern Lisp_Object Fnext_overlay_change ();
 488 extern Lisp_Object Fdelete_overlay ();
 489
 490 /* Functions to call before and after each text change.  */
 491 extern Lisp_Object Vbefore_change_function;
 492 extern Lisp_Object Vafter_change_function;
 493 extern Lisp_Object Vbefore_change_functions;
 494 extern Lisp_Object Vafter_change_functions;
 495 extern Lisp_Object Vfirst_change_hook;
 496 extern Lisp_Object Qbefore_change_functions;
 497 extern Lisp_Object Qafter_change_functions;
 498 extern Lisp_Object Qfirst_change_hook;
 499
 500 extern Lisp_Object Vdeactivate_mark;
 501 extern Lisp_Object Vtransient_mark_mode;
 502 \f
 503 /* Overlays */
 504
 505 /* 1 if the OV is an overlay object.  */
 506 #define OVERLAY_VALID(OV) (OVERLAYP (OV))
 507
 508 /* Return the marker that stands for where OV starts in the buffer.  */
 509 #define OVERLAY_START(OV) (XOVERLAY (OV)->start)
 510
 511 /* Return the marker that stands for where OV ends in the buffer.  */
 512 #define OVERLAY_END(OV) (XOVERLAY (OV)->end)
 513
 514 /* Return the actual buffer position for the marker P.
 515    We assume you know which buffer it's pointing into.  */
 516
 517 #define OVERLAY_POSITION(P) \
 518  (GC_MARKERP (P) ? marker_position (P) : (abort (), 0))
 519
 520 /* Allocation of buffer text.  */
 521
 522 #ifdef REL_ALLOC
 523 #define BUFFER_ALLOC(data,size) ((unsigned char *) r_alloc (&data, (size)))
 524 #define BUFFER_REALLOC(data,size) ((unsigned char *) r_re_alloc (&data, (size)))
 525 #define BUFFER_FREE(data) (r_alloc_free (&data))
 526 #define R_ALLOC_DECLARE(var,data) (r_alloc_declare (&var, (data)))
 527 #else
 528 #define BUFFER_ALLOC(data,size) (data = (unsigned char *) malloc ((size)))
 529 #define BUFFER_REALLOC(data,size) ((unsigned char *) realloc ((data), (size)))
 530 #define BUFFER_FREE(data) (free ((data)))
 531 #define R_ALLOC_DECLARE(var,data)
 532 #endif