src/buffer.h

   1 /* Header file for the buffer manipulation primitives.
   2    Copyright (C) 1985, 1986, 1990, 1992 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 #ifdef lint
  22 #include "undo.h"
  23 #endif /* lint */
  24
  25
  26 #ifdef USE_TEXT_PROPERTIES
  27 #define SET_PT(position) (set_point ((position), current_buffer))
  28 #define TEMP_SET_PT(position) (temp_set_point ((position), current_buffer))
  29
  30 #define BUF_SET_PT(buffer, position) (set_point ((position), (buffer)))
  31 #define BUF_TEMP_SET_PT(buffer, position) (temp_set_point ((position), (buffer)))
  32
  33 #else  /* don't support text properties */
  34
  35 #define SET_PT(position) (current_buffer->text.pt = (position))
  36 #define TEMP_SET_PT(position) (current_buffer->text.pt = (position))
  37
  38 #define BUF_SET_PT(buffer, position) (buffer->text.pt = (position))
  39 #define BUF_TEMP_SET_PT(buffer, position) (buffer->text.pt = (position))
  40 #endif /* don't support text properties */
  41
  42 /* Character position of beginning of buffer.  */
  43 #define BEG (1)
  44
  45 /* Character position of beginning of accessible range of buffer.  */
  46 #define BEGV (current_buffer->text.begv)
  47
  48 /* Character position of point in buffer.  The "+ 0" makes this
  49    not an l-value, so you can't assign to it.  Use SET_PT instead.  */
  50 #define PT (current_buffer->text.pt + 0)
  51
  52 /* Character position of gap in buffer.  */
  53 #define GPT (current_buffer->text.gpt)
  54
  55 /* Character position of end of accessible range of buffer.  */
  56 #define ZV (current_buffer->text.zv)
  57
  58 /* Character position of end of buffer.  */
  59 #define Z (current_buffer->text.z)
  60
  61 /* Modification count.  */
  62 #define MODIFF (current_buffer->text.modiff)
  63
  64 /* Address of beginning of buffer.  */
  65 #define BEG_ADDR (current_buffer->text.beg)
  66
  67 /* Address of beginning of accessible range of buffer.  */
  68 #define BEGV_ADDR (&FETCH_CHAR (current_buffer->text.begv))
  69
  70 /* Address of point in buffer.  */
  71 #define PT_ADDR (&FETCH_CHAR (current_buffer->text.pt))
  72
  73 /* Address of beginning of gap in buffer.  */
  74 #define GPT_ADDR (current_buffer->text.beg + current_buffer->text.gpt - 1)
  75
  76 /* Address of end of gap in buffer.  */
  77 #define GAP_END_ADDR (current_buffer->text.beg + current_buffer->text.gpt + current_buffer->text.gap_size - 1)
  78
  79 /* Address of end of accessible range of buffer.  */
  80 #define ZV_ADDR (&FETCH_CHAR (current_buffer->text.zv))
  81
  82 /* Size of gap.  */
  83 #define GAP_SIZE (current_buffer->text.gap_size)
  84
  85 /* Now similar macros for a specified buffer.
  86    Note that many of these evaluate the buffer argument more than once.  */
  87
  88 /* Character position of beginning of buffer.  */
  89 #define BUF_BEG(buf) (1)
  90
  91 /* Character position of beginning of accessible range of buffer.  */
  92 #define BUF_BEGV(buf) ((buf)->text.begv)
  93
  94 /* Character position of point in buffer.  */
  95 #define BUF_PT(buf) ((buf)->text.pt)
  96
  97 /* Character position of gap in buffer.  */
  98 #define BUF_GPT(buf) ((buf)->text.gpt)
  99
 100 /* Character position of end of accessible range of buffer.  */
 101 #define BUF_ZV(buf) ((buf)->text.zv)
 102
 103 /* Character position of end of buffer.  */
 104 #define BUF_Z(buf) ((buf)->text.z)
 105
 106 /* Modification count.  */
 107 #define BUF_MODIFF(buf) ((buf)->text.modiff)
 108
 109 /* Address of beginning of buffer.  */
 110 #define BUF_BEG_ADDR(buf) ((buf)->text.beg)
 111
 112 /* Macro for setting the value of BUF_ZV (BUF) to VALUE,
 113    by varying the end of the accessible region.  */
 114 #define SET_BUF_ZV(buf, value) ((buf)->text.zv = (value))
 115 #define SET_BUF_PT(buf, value) ((buf)->text.pt = (value))
 116
 117 /* Size of gap.  */
 118 #define BUF_GAP_SIZE(buf) ((buf)->text.gap_size)
 119
 120 /* Return the address of character at position POS in buffer BUF.
 121    Note that both arguments can be computed more than once.  */
 122 #define BUF_CHAR_ADDRESS(buf, pos) \
 123 ((buf)->text.beg + (pos) - 1            \
 124  + ((pos) >= (buf)->text.gpt ? (buf)->text.gap_size : 0))
 125
 126 /* Convert the address of a char in the buffer into a character position.  */
 127 #define PTR_CHAR_POS(ptr) \
 128 ((ptr) - (current_buffer)->text.beg                                     \
 129  - (ptr - (current_buffer)->text.beg < (unsigned) GPT ? 0 : GAP_SIZE)   \
 130  + 1)
 131 \f
 132 struct buffer_text
 133   {
 134     unsigned char *beg;         /* Actual address of buffer contents. */
 135     int begv;                   /* Index of beginning of accessible range. */
 136     int pt;                     /* Position of point in buffer. */
 137     int gpt;                    /* Index of gap in buffer. */
 138     int zv;                     /* Index of end of accessible range. */
 139     int z;                      /* Index of end of buffer. */
 140     int gap_size;               /* Size of buffer's gap */
 141     int modiff;                 /* This counts buffer-modification events
 142                                    for this buffer.  It is incremented for
 143                                    each such event, and never otherwise
 144                                    changed.  */
 145   };
 146
 147 struct buffer
 148   {
 149     /* Everything before the `name' slot must be of a non-Lisp_Object type,
 150        and every slot after `name' must be a Lisp_Object.
 151
 152        Check out mark_buffer (alloc.c) to see why.
 153      */
 154
 155     /* This structure holds the coordinates of the buffer contents.  */
 156     struct buffer_text text;
 157     /* Next buffer, in chain of all buffers including killed buffers.
 158        This chain is used only for garbage collection, in order to
 159        collect killed buffers properly.  */
 160     struct buffer *next;
 161     /* Flags saying which DEFVAR_PER_BUFFER variables
 162        are local to this buffer.  */
 163     int local_var_flags;
 164     /* Value of text.modiff as of when visited file was read or written. */
 165     int save_modified;
 166     /* Set to the modtime of the visited file when read or written.
 167        -1 means visited file was nonexistent.
 168        0 means visited file modtime unknown; in no case complain
 169        about any mismatch on next save attempt.  */
 170     int modtime;
 171     /* the value of text.modiff at the last auto-save. */
 172     int auto_save_modified;
 173     /* Position in buffer at which display started
 174        the last time this buffer was displayed */
 175     int last_window_start;
 176
 177     /* Properties of this buffer's text -- conditionally compiled. */
 178     DECLARE_INTERVALS
 179
 180     /* This is a special exception -- as this slot should not be
 181        marked by gc_sweep, and as it is not lisp-accessible as
 182        a local variable -- so we regard it as not really being of type
 183        Lisp_Object */
 184     /* the markers that refer to this buffer.
 185        This is actually a single marker ---
 186        successive elements in its marker `chain'
 187        are the other markers referring to this
 188        buffer */
 189     Lisp_Object markers;
 190
 191
 192     /* Everything from here down must be a Lisp_Object */
 193
 194
 195     /* the name of this buffer */
 196     Lisp_Object name;
 197     /* Nuked: buffer number, assigned when buffer made Lisp_Object number;*/
 198     /* the name of the file associated with this buffer */
 199     Lisp_Object filename;
 200     /* Dir for expanding relative pathnames */
 201     Lisp_Object directory;
 202     /* true iff this buffer has been been backed
 203        up (if you write to its associated file
 204        and it hasn't been backed up, then a
 205        backup will be made) */
 206     /* This isn't really used by the C code, so could be deleted.  */
 207     Lisp_Object backed_up;
 208     /* Length of file when last read or saved. */
 209     Lisp_Object save_length;
 210     /* file name used for auto-saving this buffer */
 211     Lisp_Object auto_save_file_name;
 212     /* Non-nil if buffer read-only */
 213     Lisp_Object read_only;
 214     /* "The mark"; no longer allowed to be nil */
 215     Lisp_Object mark;
 216
 217     /* Alist of elements (SYMBOL . VALUE-IN-THIS-BUFFER)
 218        for all per-buffer variables of this buffer.  */
 219     Lisp_Object local_var_alist;
 220
 221
 222     /* Symbol naming major mode (eg lisp-mode) */
 223     Lisp_Object major_mode;
 224     /* Pretty name of major mode (eg "Lisp") */
 225     Lisp_Object mode_name;
 226     /* Format string for mode line */
 227     Lisp_Object mode_line_format;
 228
 229     /* Keys that are bound local to this buffer */
 230     Lisp_Object keymap;
 231     /* This buffer's local abbrev table */
 232     Lisp_Object abbrev_table;
 233     /* This buffer's syntax table. */
 234     Lisp_Object syntax_table;
 235
 236     /* Values of several buffer-local variables */
 237     /* tab-width is buffer-local so that redisplay can find it
 238        in buffers that are not current */
 239     Lisp_Object case_fold_search;
 240     Lisp_Object tab_width;
 241     Lisp_Object fill_column;
 242     Lisp_Object left_margin;
 243     /* Function to call when insert space past fill column */
 244     Lisp_Object auto_fill_function;
 245
 246     /* String of length 256 mapping each char to its lower-case version.  */
 247     Lisp_Object downcase_table;
 248     /* String of length 256 mapping each char to its upper-case version.  */
 249     Lisp_Object upcase_table;
 250
 251     /* Non-nil means do not display continuation lines */
 252     Lisp_Object truncate_lines;
 253     /* Non-nil means display ctl chars with uparrow */
 254     Lisp_Object ctl_arrow;
 255     /* Non-nil means do selective display;
 256        See doc string in syms_of_buffer (buffer.c) for details.  */
 257     Lisp_Object selective_display;
 258 #ifndef old
 259     /* Non-nil means show ... at end of line followed by invisible lines.  */
 260     Lisp_Object selective_display_ellipses;
 261 #endif
 262     /* Alist of (FUNCTION . STRING) for each minor mode enabled in buffer. */
 263     Lisp_Object minor_modes;
 264     /* t if "self-insertion" should overwrite */
 265     Lisp_Object overwrite_mode;
 266     /* non-nil means abbrev mode is on.  Expand abbrevs automatically. */
 267     Lisp_Object abbrev_mode;
 268     /* Display table to use for text in this buffer. */
 269     Lisp_Object display_table;
 270     /* Translate table for case-folding search.  */
 271     Lisp_Object case_canon_table;
 272     /* Inverse translate (equivalence class) table for case-folding search.  */
 273     Lisp_Object case_eqv_table;
 274     /* Changes in the buffer are recorded here for undo.
 275        t means don't record anything.  */
 276     Lisp_Object undo_list;
 277
 278     /* List of fields in this buffer.  */
 279     Lisp_Object fieldlist;
 280 };
 281
 282 extern struct buffer *current_buffer;
 283
 284 /* This structure holds the default values of the buffer-local variables
 285    defined with DefBufferLispVar, that have special slots in each buffer.
 286    The default value occupies the same slot in this structure
 287    as an individual buffer's value occupies in that buffer.
 288    Setting the default value also goes through the alist of buffers
 289    and stores into each buffer that does not say it has a local value.  */
 290
 291 extern struct buffer buffer_defaults;
 292
 293 /* This structure marks which slots in a buffer have corresponding
 294    default values in buffer_defaults.
 295    Each such slot has a nonzero value in this structure.
 296    The value has only one nonzero bit.
 297
 298    When a buffer has its own local value for a slot,
 299    the bit for that slot (found in the same slot in this structure)
 300    is turned on in the buffer's local_var_flags slot.
 301
 302    If a slot in this structure is zero, then even though there may
 303    be a DefBufferLispVar for the slot, there is no default valuefeor it;
 304    and the corresponding slot in buffer_defaults is not used.  */
 305
 306 extern struct buffer buffer_local_flags;
 307
 308 /* For each buffer slot, this points to the Lisp symbol name
 309    for that slot in the current buffer.  It is 0 for slots
 310    that don't have such names.  */
 311
 312 extern struct buffer buffer_local_symbols;
 313
 314 /* This structure holds the required types for the values in the
 315    buffer-local slots.  If a slot contains Qnil, then the
 316    corresponding buffer slot may contain a value of any type.  If a
 317    slot contains an integer, then prospective values' tags must be
 318    equal to that integer.  When a tag does not match, the function
 319    buffer_slot_type_mismatch will signal an error.  The value Qnil may
 320    always be safely stored in any slot.  */
 321 extern struct buffer buffer_local_types;
 322
 323 /* Point in the current buffer. */
 324
 325 #define point (current_buffer->text.pt + 0)
 326
 327 /* Return character at position n.  No range checking */
 328 #define FETCH_CHAR(n) *(((n)>= GPT ? GAP_SIZE : 0) + (n) + BEG_ADDR - 1)
 329
 330 /* BUFFER_CEILING_OF (resp. BUFFER_FLOOR_OF), when applied to n, return
 331    the max (resp. min) p such that
 332
 333    &FETCH_CHAR (p) - &FETCH_CHAR (n) == p - n       */
 334
 335 #define BUFFER_CEILING_OF(n) (((n) < GPT && GPT < ZV ? GPT : ZV) - 1)
 336 #define BUFFER_FLOOR_OF(n) (BEGV <= GPT && GPT <= (n) ? GPT : BEGV)
 337
 338 extern void reset_buffer ();
 339
 340 /* Functions to call before and after each text change. */
 341 extern Lisp_Object Vbefore_change_function;
 342 extern Lisp_Object Vafter_change_function;
 343 extern Lisp_Object Vfirst_change_hook;
 344 extern Lisp_Object Qfirst_change_hook;
 345
 346 /* Fields.
 347
 348 A field is like a marker but it defines a region rather than a
 349 point.  Like a marker, a field is asocated with a buffer.
 350 The field mechanism uses the marker mechanism in the
 351 sense that its start and end points are maintained as markers
 352 updated in the usual way as the buffer changes.
 353
 354 A field can be protected or unprotected.  If it is protected,
 355 no modifications can be made that affect the field in its buffer,
 356 when protected field checking is enabled.
 357
 358 Each field also contains an alist, in which you can store
 359 whatever you like.  */
 360
 361 /* Slots in a field:  */
 362
 363 #define FIELD_BUFFER(f) (XVECTOR(f)->contents[1])
 364 #define FIELD_START_MARKER(f) (XVECTOR(f)->contents[2])
 365 #define FIELD_END_MARKER(f) (XVECTOR(f)->contents[3])
 366 #define FIELD_PROTECTED_FLAG(f) (XVECTOR(f)->contents[4])
 367 #define FIELD_ALIST(f) (XVECTOR(f)->contents[5])
 368
 369 /* Allocation of buffer data. */
 370 #ifdef REL_ALLOC
 371 #define BUFFER_ALLOC(data,size) ((unsigned char *) r_alloc (&data, (size)))
 372 #define BUFFER_REALLOC(data,size) ((unsigned char *) r_re_alloc (&data, (size)))
 373 #define BUFFER_FREE(data) (r_alloc_free (&data))
 374 #define R_ALLOC_DECLARE(var,data) (r_alloc_declare (&var, (data)))
 375 #else
 376 #define BUFFER_ALLOC(data,size) (data = (unsigned char *) malloc ((size)))
 377 #define BUFFER_REALLOC(data,size) ((unsigned char *) realloc ((data), (size)))
 378 #define BUFFER_FREE(data) (free ((data)))
 379 #define R_ALLOC_DECLARE(var,data)
 380 #endif
 381
 382 /* VAX C is non-ANSI wrt extern declarations and requires the struct
 383    re_pattern_buffer to completely defined for searchbuf's declaration.  */
 384 #ifdef VMS
 385 #include "regex.h"
 386 #endif /* VMS */
 387
 388 /* A search buffer, with a fastmap allocated and ready to go.  */
 389 extern struct re_pattern_buffer searchbuf;
 390
 391 extern Lisp_Object Fbuffer_name ();
 392 extern Lisp_Object Fget_file_buffer ();