src/buffer.h

   1 /* Header file for the buffer manipulation primitives.
   2    Copyright (C) 1985, 1986, 1990 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 #ifdef lint
  22 #include "undo.h"
  23 #endif /* lint */
  24
  25
  26 #define SET_PT(position) (current_buffer->text.pt = (position))
  27
  28 /* Character position of beginning of buffer.  */
  29 #define BEG (1)
  30
  31 /* Character position of beginning of accessible range of buffer.  */
  32 #define BEGV (current_buffer->text.begv)
  33
  34 /* Character position of point in buffer.  The "+ 0" makes this
  35    not an l-value, so you can't assign to it.  Use SET_PT instead.  */
  36 #define PT (current_buffer->text.pt + 0)
  37
  38 /* Character position of gap in buffer.  */
  39 #define GPT (current_buffer->text.gpt)
  40
  41 /* Character position of end of accessible range of buffer.  */
  42 #define ZV (current_buffer->text.zv)
  43
  44 /* Character position of end of buffer.  */
  45 #define Z (current_buffer->text.z)
  46
  47 /* Modification count.  */
  48 #define MODIFF (current_buffer->text.modiff)
  49
  50 /* Address of beginning of buffer.  */
  51 #define BEG_ADDR (current_buffer->text.beg)
  52
  53 /* Address of beginning of accessible range of buffer.  */
  54 #define BEGV_ADDR (&FETCH_CHAR (current_buffer->text.begv))
  55
  56 /* Address of point in buffer.  */
  57 #define PT_ADDR (&FETCH_CHAR (current_buffer->text.pt))
  58
  59 /* Address of beginning of gap in buffer.  */
  60 #define GPT_ADDR (current_buffer->text.beg + current_buffer->text.gpt - 1)
  61
  62 /* Address of end of gap in buffer.  */
  63 #define GAP_END_ADDR (current_buffer->text.beg + current_buffer->text.gpt + current_buffer->text.gap_size - 1)
  64
  65 /* Address of end of accessible range of buffer.  */
  66 #define ZV_ADDR (&FETCH_CHAR (current_buffer->text.zv))
  67
  68 /* Size of gap.  */
  69 #define GAP_SIZE (current_buffer->text.gap_size)
  70
  71 /* Now similar macros for a specified buffer.
  72    Note that many of these evaluate the buffer argument more than once.  */
  73
  74 /* Character position of beginning of buffer.  */
  75 #define BUF_BEG(buf) (1)
  76
  77 /* Character position of beginning of accessible range of buffer.  */
  78 #define BUF_BEGV(buf) ((buf)->text.begv)
  79
  80 /* Character position of point in buffer.  */
  81 #define BUF_PT(buf) ((buf)->text.pt)
  82
  83 /* Character position of gap in buffer.  */
  84 #define BUF_GPT(buf) ((buf)->text.gpt)
  85
  86 /* Character position of end of accessible range of buffer.  */
  87 #define BUF_ZV(buf) ((buf)->text.zv)
  88
  89 /* Character position of end of buffer.  */
  90 #define BUF_Z(buf) ((buf)->text.z)
  91
  92 /* Modification count.  */
  93 #define BUF_MODIFF(buf) ((buf)->text.modiff)
  94
  95 /* Address of beginning of buffer.  */
  96 #define BUF_BEG_ADDR(buf) ((buf)->text.beg)
  97
  98 /* Macro for setting the value of BUF_ZV (BUF) to VALUE,
  99    by varying the end of the accessible region.  */
 100 #define SET_BUF_ZV(buf, value) ((buf)->text.zv = (value))
 101 #define SET_BUF_PT(buf, value) ((buf)->text.pt = (value))
 102
 103 /* Size of gap.  */
 104 #define BUF_GAP_SIZE(buf) ((buf)->text.gap_size)
 105
 106 /* Return the address of character at position POS in buffer BUF.
 107    Note that both arguments can be computed more than once.  */
 108 #define BUF_CHAR_ADDRESS(buf, pos) \
 109 ((buf)->text.beg + (pos) - 1            \
 110  + ((pos) >= (buf)->text.gpt ? (buf)->text.gap_size : 0))
 111
 112 /* Convert the address of a char in the buffer into a character position.  */
 113 #define PTR_CHAR_POS(ptr) \
 114 ((ptr) - (current_buffer)->text.beg                                     \
 115  - (ptr - (current_buffer)->text.beg < (unsigned) GPT ? 0 : GAP_SIZE)   \
 116  + 1)
 117 \f
 118 struct buffer_text
 119   {
 120     unsigned char *beg;         /* Actual address of buffer contents. */
 121     int begv;                   /* Index of beginning of accessible range. */
 122     int pt;                     /* Position of point in buffer. */
 123     int gpt;                    /* Index of gap in buffer. */
 124     int zv;                     /* Index of end of accessible range. */
 125     int z;                      /* Index of end of buffer. */
 126     int gap_size;               /* Size of buffer's gap */
 127     int modiff;                 /* This counts buffer-modification events
 128                                    for this buffer.  It is incremented for
 129                                    each such event, and never otherwise
 130                                    changed.  */
 131   };
 132
 133 struct buffer
 134   {
 135     /* Everything before the `name' slot must be of a non-Lisp_Object type,
 136        and every slot after `name' must be a Lisp_Object.
 137
 138        Check out mark_buffer (alloc.c) to see why.
 139      */
 140
 141     /* This structure holds the coordinates of the buffer contents.  */
 142     struct buffer_text text;
 143     /* Next buffer, in chain of all buffers including killed buffers.
 144        This chain is used only for garbage collection, in order to
 145        collect killed buffers properly.  */
 146     struct buffer *next;
 147     /* Flags saying which DEFVAR_PER_BUFFER variables
 148        are local to this buffer.  */
 149     int local_var_flags;
 150     /* Value of text.modiff as of when visited file was read or written. */
 151     int save_modified;
 152     /* Set to the modtime of the visited file when read or written.
 153        -1 means visited file was nonexistent.
 154        0 means visited file modtime unknown; in no case complain
 155        about any mismatch on next save attempt.  */
 156     int modtime;
 157     /* the value of text.modiff at the last auto-save. */
 158     int auto_save_modified;
 159     /* Position in buffer at which display started
 160        the last time this buffer was displayed */
 161     int last_window_start;
 162
 163     /* This is a special exception -- as this slot should not be
 164        marked by gc_sweep, and as it is not lisp-accessible as
 165        a local variable -- so we regard it as not really being of type
 166        Lisp_Object */
 167     /* the markers that refer to this buffer.
 168        This is actually a single marker ---
 169        successive elements in its marker `chain'
 170        are the other markers referring to this
 171        buffer */
 172     Lisp_Object markers;
 173
 174
 175     /* Everything from here down must be a Lisp_Object */
 176
 177
 178     /* the name of this buffer */
 179     Lisp_Object name;
 180     /* Nuked: buffer number, assigned when buffer made Lisp_Object number;*/
 181     /* the name of the file associated with this buffer */
 182     Lisp_Object filename;
 183     /* Dir for expanding relative pathnames */
 184     Lisp_Object directory;
 185     /* true iff this buffer has been been backed
 186        up (if you write to its associated file
 187        and it hasn't been backed up, then a
 188        backup will be made) */
 189     /* This isn't really used by the C code, so could be deleted.  */
 190     Lisp_Object backed_up;
 191     /* Length of file when last read or saved. */
 192     Lisp_Object save_length;
 193     /* file name used for auto-saving this buffer */
 194     Lisp_Object auto_save_file_name;
 195     /* Non-nil if buffer read-only */
 196     Lisp_Object read_only;
 197     /* "The mark"; no longer allowed to be nil */
 198     Lisp_Object mark;
 199
 200     /* Alist of elements (SYMBOL . VALUE-IN-THIS-BUFFER)
 201        for all per-buffer variables of this buffer.  */
 202     Lisp_Object local_var_alist;
 203
 204
 205     /* Symbol naming major mode (eg lisp-mode) */
 206     Lisp_Object major_mode;
 207     /* Pretty name of major mode (eg "Lisp") */
 208     Lisp_Object mode_name;
 209     /* Format string for mode line */
 210     Lisp_Object mode_line_format;
 211
 212     /* Keys that are bound local to this buffer */
 213     Lisp_Object keymap;
 214     /* This buffer's local abbrev table */
 215     Lisp_Object abbrev_table;
 216     /* This buffer's syntax table. */
 217     Lisp_Object syntax_table;
 218
 219     /* Values of several buffer-local variables */
 220     /* tab-width is buffer-local so that redisplay can find it
 221        in buffers that are not current */
 222     Lisp_Object case_fold_search;
 223     Lisp_Object tab_width;
 224     Lisp_Object fill_column;
 225     Lisp_Object left_margin;
 226     /* Function to call when insert space past fill column */
 227     Lisp_Object auto_fill_function;
 228
 229     /* String of length 256 mapping each char to its lower-case version.  */
 230     Lisp_Object downcase_table;
 231     /* String of length 256 mapping each char to its upper-case version.  */
 232     Lisp_Object upcase_table;
 233
 234     /* Non-nil means do not display continuation lines */
 235     Lisp_Object truncate_lines;
 236     /* Non-nil means display ctl chars with uparrow */
 237     Lisp_Object ctl_arrow;
 238     /* Non-nil means do selective display;
 239        See doc string in syms_of_buffer (buffer.c) for details.  */
 240     Lisp_Object selective_display;
 241 #ifndef old
 242     /* Non-nil means show ... at end of line followed by invisible lines.  */
 243     Lisp_Object selective_display_ellipses;
 244 #endif
 245     /* Alist of (FUNCTION . STRING) for each minor mode enabled in buffer. */
 246     Lisp_Object minor_modes;
 247     /* t if "self-insertion" should overwrite */
 248     Lisp_Object overwrite_mode;
 249     /* non-nil means abbrev mode is on.  Expand abbrevs automatically. */
 250     Lisp_Object abbrev_mode;
 251     /* Display table to use for text in this buffer. */
 252     Lisp_Object display_table;
 253     /* Translate table for case-folding search.  */
 254     Lisp_Object case_canon_table;
 255     /* Inverse translate (equivalence class) table for case-folding search.  */
 256     Lisp_Object case_eqv_table;
 257     /* Changes in the buffer are recorded here for undo.
 258        t means don't record anything.  */
 259     Lisp_Object undo_list;
 260
 261     /* List of fields in this buffer.  */
 262     Lisp_Object fieldlist;
 263 };
 264
 265 extern struct buffer *current_buffer;
 266
 267 /* This structure holds the default values of the buffer-local variables
 268    defined with DefBufferLispVar, that have special slots in each buffer.
 269    The default value occupies the same slot in this structure
 270    as an individual buffer's value occupies in that buffer.
 271    Setting the default value also goes through the alist of buffers
 272    and stores into each buffer that does not say it has a local value.  */
 273
 274 extern struct buffer buffer_defaults;
 275
 276 /* This structure marks which slots in a buffer have corresponding
 277    default values in buffer_defaults.
 278    Each such slot has a nonzero value in this structure.
 279    The value has only one nonzero bit.
 280
 281    When a buffer has its own local value for a slot,
 282    the bit for that slot (found in the same slot in this structure)
 283    is turned on in the buffer's local_var_flags slot.
 284
 285    If a slot in this structure is zero, then even though there may
 286    be a DefBufferLispVar for the slot, there is no default valuefeor it;
 287    and the corresponding slot in buffer_defaults is not used.  */
 288
 289 extern struct buffer buffer_local_flags;
 290
 291 /* For each buffer slot, this points to the Lisp symbol name
 292    for that slot in the current buffer.  It is 0 for slots
 293    that don't have such names.  */
 294
 295 extern struct buffer buffer_local_symbols;
 296
 297 /* Point in the current buffer. */
 298
 299 #define point (current_buffer->text.pt + 0)
 300
 301 /* Return character at position n.  No range checking */
 302 #define FETCH_CHAR(n) *(((n)>= GPT ? GAP_SIZE : 0) + (n) + BEG_ADDR - 1)
 303
 304 /* BUFFER_CEILING_OF (resp. BUFFER_FLOOR_OF), when applied to n, return
 305    the max (resp. min) p such that
 306
 307    &FETCH_CHAR (p) - &FETCH_CHAR (n) == p - n       */
 308
 309 #define BUFFER_CEILING_OF(n) (((n) < GPT && GPT < ZV ? GPT : ZV) - 1)
 310 #define BUFFER_FLOOR_OF(n) (BEGV <= GPT && GPT <= (n) ? GPT : BEGV)
 311
 312 extern void reset_buffer ();
 313
 314 /* Functions to call before and after each text change. */
 315 extern Lisp_Object Vbefore_change_function;
 316 extern Lisp_Object Vafter_change_function;
 317 extern Lisp_Object Vfirst_change_function;
 318
 319 /* Fields.
 320
 321 A field is like a marker but it defines a region rather than a
 322 point.  Like a marker, a field is asocated with a buffer.
 323 The field mechanism uses the marker mechanism in the
 324 sense that its start and end points are maintained as markers
 325 updated in the usual way as the buffer changes.
 326
 327 A field can be protected or unprotected.  If it is protected,
 328 no modifications can be made that affect the field in its buffer,
 329 when protected field checking is enabled.
 330
 331 Each field also contains an alist, in which you can store
 332 whatever you like.  */
 333
 334 /* Slots in a field:  */
 335
 336 #define FIELD_BUFFER(f) (XVECTOR(f)->contents[1])
 337 #define FIELD_START_MARKER(f) (XVECTOR(f)->contents[2])
 338 #define FIELD_END_MARKER(f) (XVECTOR(f)->contents[3])
 339 #define FIELD_PROTECTED_FLAG(f) (XVECTOR(f)->contents[4])
 340 #define FIELD_ALIST(f) (XVECTOR(f)->contents[5])
 341
 342 /* Allocation of buffer data. */
 343 #ifdef REL_ALLOC
 344 #define BUFFER_ALLOC(data,size) ((unsigned char *) r_alloc (&data, (size)))
 345 #define BUFFER_REALLOC(data,size) ((unsigned char *) r_re_alloc (&data, (size)))
 346 #define BUFFER_FREE(data) (r_alloc_free (&data))
 347 #define R_ALLOC_DECLARE(var,data) (r_alloc_declare (&var, (data)))
 348 #else
 349 #define BUFFER_ALLOC(data,size) (data = (unsigned char *) malloc ((size)))
 350 #define BUFFER_REALLOC(data,size) ((unsigned char *) realloc ((data), (size)))
 351 #define BUFFER_FREE(data) (free ((data)))
 352 #define R_ALLOC_DECLARE(var,data)
 353 #endif
 354
 355 /* A search buffer, with a fastmap allocated and ready to go.  */
 356 extern struct re_pattern_buffer searchbuf;