src/character.h

   1 /* Header for multibyte character handler.
   2    Copyright (C) 1995, 1997, 1998 Electrotechnical Laboratory, JAPAN.
   3      Licensed to the Free Software Foundation.
   4    Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
   5      National Institute of Advanced Industrial Science and Technology (AIST)
   6      Registration Number H13PRO009
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software: you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation, either version 3 of the License, or
  13 (at your option) any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #ifndef EMACS_CHARACTER_H
  24 #define EMACS_CHARACTER_H
  25
  26 /* character code       1st byte   byte sequence
  27    --------------       --------   -------------
  28         0-7F            00..7F     0xxxxxxx
  29        80-7FF           C2..DF     110xxxxx 10xxxxxx
  30       800-FFFF          E0..EF     1110xxxx 10xxxxxx 10xxxxxx
  31     10000-1FFFFF        F0..F7     11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
  32    200000-3FFF7F        F8         11111000 1000xxxx 10xxxxxx 10xxxxxx 10xxxxxx
  33    3FFF80-3FFFFF        C0..C1     1100000x 10xxxxxx (for eight-bit-char)
  34    400000-...           invalid
  35
  36    invalid 1st byte     80..BF     10xxxxxx
  37                         F9..FF     11111xxx (xxx != 000)
  38 */
  39
  40 /* Maximum character code ((1 << CHARACTERBITS) - 1).  */
  41 #define MAX_CHAR  0x3FFFFF
  42
  43 /* Maximum Unicode character code.  */
  44 #define MAX_UNICODE_CHAR 0x10FFFF
  45
  46 /* Maximum N-byte character codes.  */
  47 #define MAX_1_BYTE_CHAR 0x7F
  48 #define MAX_2_BYTE_CHAR 0x7FF
  49 #define MAX_3_BYTE_CHAR 0xFFFF
  50 #define MAX_4_BYTE_CHAR 0x1FFFFF
  51 #define MAX_5_BYTE_CHAR 0x3FFF7F
  52
  53 /* Minimum leading code of multibyte characters.  */
  54 #define MIN_MULTIBYTE_LEADING_CODE 0xC0
  55 /* Maximum leading code of multibyte characters.  */
  56 #define MAX_MULTIBYTE_LEADING_CODE 0xF8
  57
  58 /* Nonzero iff C is a character that corresponds to a raw 8-bit
  59    byte.  */
  60 #define CHAR_BYTE8_P(c) ((c) > MAX_5_BYTE_CHAR)
  61
  62 /* Return the character code for raw 8-bit byte BYTE.  */
  63 #define BYTE8_TO_CHAR(byte) ((byte) + 0x3FFF00)
  64
  65 #define UNIBYTE_TO_CHAR(byte) \
  66   (ASCII_BYTE_P (byte) ? (byte) : BYTE8_TO_CHAR (byte))
  67
  68 /* Return the raw 8-bit byte for character C.  */
  69 #define CHAR_TO_BYTE8(c)        \
  70   (CHAR_BYTE8_P (c)             \
  71    ? (c) - 0x3FFF00             \
  72    : multibyte_char_to_unibyte (c, Qnil))
  73
  74 /* Return the raw 8-bit byte for character C,
  75    or -1 if C doesn't correspond to a byte.  */
  76 #define CHAR_TO_BYTE_SAFE(c)    \
  77   (CHAR_BYTE8_P (c)             \
  78    ? (c) - 0x3FFF00             \
  79    : multibyte_char_to_unibyte_safe (c))
  80
  81 /* Nonzero iff BYTE is the 1st byte of a multibyte form of a character
  82    that corresponds to a raw 8-bit byte.  */
  83 #define CHAR_BYTE8_HEAD_P(byte) ((byte) == 0xC0 || (byte) == 0xC1)
  84
  85 /* If C is not ASCII, make it unibyte. */
  86 #define MAKE_CHAR_UNIBYTE(c)    \
  87   do {                          \
  88     if (! ASCII_CHAR_P (c))     \
  89       c = CHAR_TO_BYTE8 (c);    \
  90   } while (0)
  91
  92
  93 /* If C is not ASCII, make it multibyte.  Assumes C < 256.  */
  94 #define MAKE_CHAR_MULTIBYTE(c) \
  95   (eassert ((c) >= 0 && (c) < 256), (c) = UNIBYTE_TO_CHAR (c))
  96
  97 /* This is the maximum byte length of multibyte form.  */
  98 #define MAX_MULTIBYTE_LENGTH 5
  99
 100 /* Return a Lisp character whose character code is C.  Assumes C is
 101    a valid character code.  */
 102 #define make_char(c) make_number (c)
 103
 104 /* Nonzero iff C is an ASCII byte.  */
 105 #define ASCII_BYTE_P(c) ((unsigned) (c) < 0x80)
 106
 107 /* Nonzero iff X is a character.  */
 108 #define CHARACTERP(x) (NATNUMP (x) && XFASTINT (x) <= MAX_CHAR)
 109
 110 /* Nonzero iff C is valid as a character code.  GENERICP is not used.  */
 111 #define CHAR_VALID_P(c, genericp) ((unsigned) (c) <= MAX_CHAR)
 112
 113 /* Check if Lisp object X is a character or not.  */
 114 #define CHECK_CHARACTER(x) \
 115   CHECK_TYPE (CHARACTERP (x), Qcharacterp, x)
 116
 117 #define CHECK_CHARACTER_CAR(x) \
 118   do {                                  \
 119     Lisp_Object tmp = XCAR (x);         \
 120     CHECK_CHARACTER (tmp);              \
 121     XSETCAR ((x), tmp);                 \
 122   } while (0)
 123
 124 #define CHECK_CHARACTER_CDR(x) \
 125   do {                                  \
 126     Lisp_Object tmp = XCDR (x);         \
 127     CHECK_CHARACTER (tmp);              \
 128     XSETCDR ((x), tmp);                 \
 129   } while (0)
 130
 131 /* Nonzero iff C is an ASCII character.  */
 132 #define ASCII_CHAR_P(c) ((unsigned) (c) < 0x80)
 133
 134 /* Nonzero iff C is a character of code less than 0x100.  */
 135 #define SINGLE_BYTE_CHAR_P(c) ((unsigned) (c) < 0x100)
 136
 137 /* Nonzero if character C has a printable glyph.  */
 138 #define CHAR_PRINTABLE_P(c)     \
 139   (((c) >= 32 && (c) < 127)     \
 140    || ! NILP (CHAR_TABLE_REF (Vprintable_chars, (c))))
 141
 142 /* Return byte length of multibyte form for character C.  */
 143 #define CHAR_BYTES(c)                   \
 144   ( (c) <= MAX_1_BYTE_CHAR ? 1          \
 145     : (c) <= MAX_2_BYTE_CHAR ? 2        \
 146     : (c) <= MAX_3_BYTE_CHAR ? 3        \
 147     : (c) <= MAX_4_BYTE_CHAR ? 4        \
 148     : (c) <= MAX_5_BYTE_CHAR ? 5        \
 149     : 2)
 150
 151
 152 /* Return the leading code of multibyte form of C.  */
 153 #define CHAR_LEADING_CODE(c)                            \
 154   ((c) <= MAX_1_BYTE_CHAR ? c                           \
 155    : (c) <= MAX_2_BYTE_CHAR ? (0xC0 | ((c) >> 6))       \
 156    : (c) <= MAX_3_BYTE_CHAR ? (0xE0 | ((c) >> 12))      \
 157    : (c) <= MAX_4_BYTE_CHAR ? (0xF0 | ((c) >> 18))      \
 158    : (c) <= MAX_5_BYTE_CHAR ? 0xF8                      \
 159    : (0xC0 | (((c) >> 6) & 0x01)))
 160
 161
 162 /* Store multibyte form of the character C in P.  The caller should
 163    allocate at least MAX_MULTIBYTE_LENGTH bytes area at P in advance.
 164    Returns the length of the multibyte form.  */
 165
 166 #define CHAR_STRING(c, p)                       \
 167   ((unsigned) (c) <= MAX_1_BYTE_CHAR            \
 168    ? ((p)[0] = (c),                             \
 169       1)                                        \
 170    : (unsigned) (c) <= MAX_2_BYTE_CHAR          \
 171    ? ((p)[0] = (0xC0 | ((c) >> 6)),             \
 172       (p)[1] = (0x80 | ((c) & 0x3F)),           \
 173       2)                                        \
 174    : (unsigned) (c) <= MAX_3_BYTE_CHAR          \
 175    ? ((p)[0] = (0xE0 | ((c) >> 12)),            \
 176       (p)[1] = (0x80 | (((c) >> 6) & 0x3F)),    \
 177       (p)[2] = (0x80 | ((c) & 0x3F)),           \
 178       3)                                        \
 179    : char_string ((unsigned) c, p))
 180
 181 /* Store multibyte form of byte B in P.  The caller should allocate at
 182    least MAX_MULTIBYTE_LENGTH bytes area at P in advance.  Returns the
 183    length of the multibyte form.  */
 184
 185 #define BYTE8_STRING(b, p)                      \
 186   ((p)[0] = (0xC0 | (((b) >> 6) & 0x01)),       \
 187    (p)[1] = (0x80 | ((b) & 0x3F)),              \
 188    2)
 189
 190
 191 /* Store multibyte form of the character C in P and advance P to the
 192    end of the multibyte form.  The caller should allocate at least
 193    MAX_MULTIBYTE_LENGTH bytes area at P in advance.  */
 194
 195 #define CHAR_STRING_ADVANCE(c, p)               \
 196   do {                                          \
 197     if ((c) <= MAX_1_BYTE_CHAR)                 \
 198       *(p)++ = (c);                             \
 199     else if ((c) <= MAX_2_BYTE_CHAR)            \
 200       *(p)++ = (0xC0 | ((c) >> 6)),             \
 201         *(p)++ = (0x80 | ((c) & 0x3F));         \
 202     else if ((c) <= MAX_3_BYTE_CHAR)            \
 203       *(p)++ = (0xE0 | ((c) >> 12)),            \
 204         *(p)++ = (0x80 | (((c) >> 6) & 0x3F)),  \
 205         *(p)++ = (0x80 | ((c) & 0x3F));         \
 206     else                                        \
 207       (p) += char_string ((c), (p));            \
 208   } while (0)
 209
 210
 211 /* Nonzero iff BYTE starts a non-ASCII character in a multibyte
 212    form.  */
 213 #define LEADING_CODE_P(byte) (((byte) & 0xC0) == 0xC0)
 214
 215 /* Nonzero iff BYTE is a trailing code of a non-ASCII character in a
 216    multibyte form.  */
 217 #define TRAILING_CODE_P(byte) (((byte) & 0xC0) == 0x80)
 218
 219 /* Nonzero iff BYTE starts a character in a multibyte form.
 220    This is equivalent to:
 221         (ASCII_BYTE_P (byte) || LEADING_CODE_P (byte))  */
 222 #define CHAR_HEAD_P(byte) (((byte) & 0xC0) != 0x80)
 223
 224 /* Kept for backward compatibility.  This macro will be removed in the
 225    future.  */
 226 #define BASE_LEADING_CODE_P LEADING_CODE_P
 227
 228 /* How many bytes a character that starts with BYTE occupies in a
 229    multibyte form.  */
 230 #define BYTES_BY_CHAR_HEAD(byte)        \
 231   (!((byte) & 0x80) ? 1                 \
 232    : !((byte) & 0x20) ? 2               \
 233    : !((byte) & 0x10) ? 3               \
 234    : !((byte) & 0x08) ? 4               \
 235    : 5)
 236
 237
 238 /* Return the length of the multi-byte form at string STR of length
 239    LEN while assuming that STR points a valid multi-byte form.  As
 240    this macro isn't necessary anymore, all callers will be changed to
 241    use BYTES_BY_CHAR_HEAD directly in the future.  */
 242
 243 #define MULTIBYTE_FORM_LENGTH(str, len)         \
 244   BYTES_BY_CHAR_HEAD (*(str))
 245
 246 /* Parse multibyte string STR of length LENGTH and set BYTES to the
 247    byte length of a character at STR while assuming that STR points a
 248    valid multibyte form.  As this macro isn't necessary anymore, all
 249    callers will be changed to use BYTES_BY_CHAR_HEAD directly in the
 250    future.  */
 251
 252 #define PARSE_MULTIBYTE_SEQ(str, length, bytes) \
 253   (bytes) = BYTES_BY_CHAR_HEAD (*(str))
 254
 255 /* The byte length of multibyte form at unibyte string P ending at
 256    PEND.  If STR doesn't point to a valid multibyte form, return 0.  */
 257
 258 #define MULTIBYTE_LENGTH(p, pend)                               \
 259   (p >= pend ? 0                                                \
 260    : !((p)[0] & 0x80) ? 1                                       \
 261    : ((p + 1 >= pend) || (((p)[1] & 0xC0) != 0x80)) ? 0         \
 262    : ((p)[0] & 0xE0) == 0xC0 ? 2                                \
 263    : ((p + 2 >= pend) || (((p)[2] & 0xC0) != 0x80)) ? 0         \
 264    : ((p)[0] & 0xF0) == 0xE0 ? 3                                \
 265    : ((p + 3 >= pend) || (((p)[3] & 0xC0) != 0x80)) ? 0         \
 266    : ((p)[0] & 0xF8) == 0xF0 ? 4                                \
 267    : ((p + 4 >= pend) || (((p)[4] & 0xC0) != 0x80)) ? 0         \
 268    : (p)[0] == 0xF8 && ((p)[1] & 0xF0) == 0x80 ? 5              \
 269    : 0)
 270
 271
 272 /* Like MULTIBYTE_LENGTH, but don't check the ending address.  */
 273
 274 #define MULTIBYTE_LENGTH_NO_CHECK(p)                    \
 275   (!((p)[0] & 0x80) ? 1                                 \
 276    : ((p)[1] & 0xC0) != 0x80 ? 0                        \
 277    : ((p)[0] & 0xE0) == 0xC0 ? 2                        \
 278    : ((p)[2] & 0xC0) != 0x80 ? 0                        \
 279    : ((p)[0] & 0xF0) == 0xE0 ? 3                        \
 280    : ((p)[3] & 0xC0) != 0x80 ? 0                        \
 281    : ((p)[0] & 0xF8) == 0xF0 ? 4                        \
 282    : ((p)[4] & 0xC0) != 0x80 ? 0                        \
 283    : (p)[0] == 0xF8 && ((p)[1] & 0xF0) == 0x80 ? 5      \
 284    : 0)
 285
 286 /* If P is before LIMIT, advance P to the next character boundary.
 287    Assumes that P is already at a character boundary of the same
 288    multibyte form whose end address is LIMIT.  */
 289
 290 #define NEXT_CHAR_BOUNDARY(p, limit)    \
 291   do {                                  \
 292     if ((p) < (limit))                  \
 293       (p) += BYTES_BY_CHAR_HEAD (*(p)); \
 294   } while (0)
 295
 296
 297 /* If P is after LIMIT, advance P to the previous character boundary.
 298    Assumes that P is already at a character boundary of the same
 299    multibyte form whose beginning address is LIMIT.  */
 300
 301 #define PREV_CHAR_BOUNDARY(p, limit)                                    \
 302   do {                                                                  \
 303     if ((p) > (limit))                                                  \
 304       {                                                                 \
 305         const unsigned char *p0 = (p);                                  \
 306         do {                                                            \
 307           p0--;                                                         \
 308         } while (p0 >= limit && ! CHAR_HEAD_P (*p0));                   \
 309         (p) = (BYTES_BY_CHAR_HEAD (*p0) == (p) - p0) ? p0 : (p) - 1;    \
 310       }                                                                 \
 311   } while (0)
 312
 313 /* Return the character code of character whose multibyte form is at
 314    P.  */
 315
 316 #define STRING_CHAR(p)                                          \
 317   (!((p)[0] & 0x80)                                             \
 318    ? (p)[0]                                                     \
 319    : ! ((p)[0] & 0x20)                                          \
 320    ? (((((p)[0] & 0x1F) << 6)                                   \
 321        | ((p)[1] & 0x3F))                                       \
 322       + (((unsigned char) (p)[0]) < 0xC2 ? 0x3FFF80 : 0))       \
 323    : ! ((p)[0] & 0x10)                                          \
 324    ? ((((p)[0] & 0x0F) << 12)                                   \
 325       | (((p)[1] & 0x3F) << 6)                                  \
 326       | ((p)[2] & 0x3F))                                        \
 327    : string_char ((p), NULL, NULL))
 328
 329
 330 /* Like STRING_CHAR, but set ACTUAL_LEN to the length of multibyte
 331    form.  */
 332
 333 #define STRING_CHAR_AND_LENGTH(p, actual_len)                   \
 334   (!((p)[0] & 0x80)                                             \
 335    ? ((actual_len) = 1, (p)[0])                                 \
 336    : ! ((p)[0] & 0x20)                                          \
 337    ? ((actual_len) = 2,                                         \
 338       (((((p)[0] & 0x1F) << 6)                                  \
 339         | ((p)[1] & 0x3F))                                      \
 340        + (((unsigned char) (p)[0]) < 0xC2 ? 0x3FFF80 : 0)))     \
 341    : ! ((p)[0] & 0x10)                                          \
 342    ? ((actual_len) = 3,                                         \
 343       ((((p)[0] & 0x0F) << 12)                                  \
 344        | (((p)[1] & 0x3F) << 6)                                 \
 345        | ((p)[2] & 0x3F)))                                      \
 346    : string_char ((p), NULL, &actual_len))
 347
 348
 349 /* Like STRING_CHAR, but advance P to the end of multibyte form.  */
 350
 351 #define STRING_CHAR_ADVANCE(p)                                  \
 352   (!((p)[0] & 0x80)                                             \
 353    ? *(p)++                                                     \
 354    : ! ((p)[0] & 0x20)                                          \
 355    ? ((p) += 2,                                                 \
 356       ((((p)[-2] & 0x1F) << 6)                                  \
 357        | ((p)[-1] & 0x3F)                                       \
 358        | ((unsigned char) ((p)[-2]) < 0xC2 ? 0x3FFF80 : 0)))    \
 359    : ! ((p)[0] & 0x10)                                          \
 360    ? ((p) += 3,                                                 \
 361       ((((p)[-3] & 0x0F) << 12)                                 \
 362        | (((p)[-2] & 0x3F) << 6)                                \
 363        | ((p)[-1] & 0x3F)))                                     \
 364    : string_char ((p), &(p), NULL))
 365
 366
 367 /* Fetch the "next" character from Lisp string STRING at byte position
 368    BYTEIDX, character position CHARIDX.  Store it into OUTPUT.
 369
 370    All the args must be side-effect-free.
 371    BYTEIDX and CHARIDX must be lvalues;
 372    we increment them past the character fetched.  */
 373
 374 #define FETCH_STRING_CHAR_ADVANCE(OUTPUT, STRING, CHARIDX, BYTEIDX)     \
 375   do                                                                    \
 376     {                                                                   \
 377       CHARIDX++;                                                        \
 378       if (STRING_MULTIBYTE (STRING))                                    \
 379         {                                                               \
 380           unsigned char *ptr = &SDATA (STRING)[BYTEIDX];                \
 381           int len;                                                      \
 382                                                                         \
 383           OUTPUT = STRING_CHAR_AND_LENGTH (ptr, len);                   \
 384           BYTEIDX += len;                                               \
 385         }                                                               \
 386       else                                                              \
 387         {                                                               \
 388           OUTPUT = SREF (STRING, BYTEIDX);                              \
 389           BYTEIDX++;                                                    \
 390         }                                                               \
 391     }                                                                   \
 392   while (0)
 393
 394 /* Like FETCH_STRING_CHAR_ADVANCE, but return a multibyte character
 395    even if STRING is unibyte.  */
 396
 397 #define FETCH_STRING_CHAR_AS_MULTIBYTE_ADVANCE(OUTPUT, STRING, CHARIDX, BYTEIDX) \
 398   do                                                                          \
 399     {                                                                         \
 400       CHARIDX++;                                                              \
 401       if (STRING_MULTIBYTE (STRING))                                          \
 402         {                                                                     \
 403           unsigned char *ptr = &SDATA (STRING)[BYTEIDX];                      \
 404           int len;                                                            \
 405                                                                               \
 406           OUTPUT = STRING_CHAR_AND_LENGTH (ptr, len);                         \
 407           BYTEIDX += len;                                                     \
 408         }                                                                     \
 409       else                                                                    \
 410         {                                                                     \
 411           OUTPUT = SREF (STRING, BYTEIDX);                                    \
 412           BYTEIDX++;                                                          \
 413           MAKE_CHAR_MULTIBYTE (OUTPUT);                                       \
 414         }                                                                     \
 415     }                                                                         \
 416   while (0)
 417
 418
 419 /* Like FETCH_STRING_CHAR_ADVANCE, but assumes STRING is multibyte.  */
 420
 421 #define FETCH_STRING_CHAR_ADVANCE_NO_CHECK(OUTPUT, STRING, CHARIDX, BYTEIDX) \
 422   do                                                                         \
 423     {                                                                        \
 424       unsigned char *ptr = &SDATA (STRING)[BYTEIDX];                         \
 425       int len;                                                               \
 426                                                                              \
 427       OUTPUT = STRING_CHAR_AND_LENGTH (ptr, len);                            \
 428       BYTEIDX += len;                                                        \
 429       CHARIDX++;                                                             \
 430     }                                                                        \
 431   while (0)
 432
 433
 434 /* Like FETCH_STRING_CHAR_ADVANCE, but fetch character from the current
 435    buffer.  */
 436
 437 #define FETCH_CHAR_ADVANCE(OUTPUT, CHARIDX, BYTEIDX)            \
 438   do                                                            \
 439     {                                                           \
 440       CHARIDX++;                                                \
 441       if (!NILP (current_buffer->enable_multibyte_characters))  \
 442         {                                                       \
 443           unsigned char *ptr = BYTE_POS_ADDR (BYTEIDX);         \
 444           int len;                                              \
 445                                                                 \
 446           OUTPUT= STRING_CHAR_AND_LENGTH (ptr, len);            \
 447           BYTEIDX += len;                                       \
 448         }                                                       \
 449       else                                                      \
 450         {                                                       \
 451           OUTPUT = *(BYTE_POS_ADDR (BYTEIDX));                  \
 452           BYTEIDX++;                                            \
 453         }                                                       \
 454     }                                                           \
 455   while (0)
 456
 457
 458 /* Like FETCH_CHAR_ADVANCE, but assumes the current buffer is multibyte.  */
 459
 460 #define FETCH_CHAR_ADVANCE_NO_CHECK(OUTPUT, CHARIDX, BYTEIDX)   \
 461   do                                                            \
 462     {                                                           \
 463       unsigned char *ptr = BYTE_POS_ADDR (BYTEIDX);             \
 464       int len;                                                  \
 465                                                                 \
 466       OUTPUT = STRING_CHAR_AND_LENGTH (ptr, len);               \
 467       BYTEIDX += len;                                           \
 468       CHARIDX++;                                                \
 469     }                                                           \
 470   while (0)
 471
 472
 473 /* Increment the buffer byte position POS_BYTE of the current buffer to
 474    the next character boundary.  No range checking of POS.  */
 475
 476 #define INC_POS(pos_byte)                               \
 477   do {                                                  \
 478     unsigned char *p = BYTE_POS_ADDR (pos_byte);        \
 479     pos_byte += BYTES_BY_CHAR_HEAD (*p);                \
 480   } while (0)
 481
 482
 483 /* Decrement the buffer byte position POS_BYTE of the current buffer to
 484    the previous character boundary.  No range checking of POS.  */
 485
 486 #define DEC_POS(pos_byte)                       \
 487   do {                                          \
 488     unsigned char *p;                           \
 489                                                 \
 490     pos_byte--;                                 \
 491     if (pos_byte < GPT_BYTE)                    \
 492       p = BEG_ADDR + pos_byte - BEG_BYTE;       \
 493     else                                        \
 494       p = BEG_ADDR + GAP_SIZE + pos_byte - BEG_BYTE;\
 495     while (!CHAR_HEAD_P (*p))                   \
 496       {                                         \
 497         p--;                                    \
 498         pos_byte--;                             \
 499       }                                         \
 500   } while (0)
 501
 502 /* Increment both CHARPOS and BYTEPOS, each in the appropriate way.  */
 503
 504 #define INC_BOTH(charpos, bytepos)                              \
 505   do                                                            \
 506     {                                                           \
 507       (charpos)++;                                              \
 508       if (NILP (current_buffer->enable_multibyte_characters))   \
 509         (bytepos)++;                                            \
 510       else                                                      \
 511         INC_POS ((bytepos));                                    \
 512     }                                                           \
 513   while (0)
 514
 515
 516 /* Decrement both CHARPOS and BYTEPOS, each in the appropriate way.  */
 517
 518 #define DEC_BOTH(charpos, bytepos)                              \
 519   do                                                            \
 520     {                                                           \
 521       (charpos)--;                                              \
 522       if (NILP (current_buffer->enable_multibyte_characters))   \
 523         (bytepos)--;                                            \
 524       else                                                      \
 525         DEC_POS ((bytepos));                                    \
 526     }                                                           \
 527   while (0)
 528
 529
 530 /* Increment the buffer byte position POS_BYTE of the current buffer to
 531    the next character boundary.  This macro relies on the fact that
 532    *GPT_ADDR and *Z_ADDR are always accessible and the values are
 533    '\0'.  No range checking of POS_BYTE.  */
 534
 535 #define BUF_INC_POS(buf, pos_byte)                              \
 536   do {                                                          \
 537     unsigned char *p = BUF_BYTE_ADDRESS (buf, pos_byte);        \
 538     pos_byte += BYTES_BY_CHAR_HEAD (*p);                        \
 539   } while (0)
 540
 541
 542 /* Decrement the buffer byte position POS_BYTE of the current buffer to
 543    the previous character boundary.  No range checking of POS_BYTE.  */
 544
 545 #define BUF_DEC_POS(buf, pos_byte)                                      \
 546   do {                                                                  \
 547     unsigned char *p;                                                   \
 548     pos_byte--;                                                         \
 549     if (pos_byte < BUF_GPT_BYTE (buf))                                  \
 550       p = BUF_BEG_ADDR (buf) + pos_byte - BEG_BYTE;                     \
 551     else                                                                \
 552       p = BUF_BEG_ADDR (buf) + BUF_GAP_SIZE (buf) + pos_byte - BEG_BYTE;\
 553     while (!CHAR_HEAD_P (*p))                                           \
 554       {                                                                 \
 555         p--;                                                            \
 556         pos_byte--;                                                     \
 557       }                                                                 \
 558   } while (0)
 559
 560
 561 /* If C is a character to be unified with a Unicode character, return
 562    the unified Unicode character.  */
 563
 564 #define MAYBE_UNIFY_CHAR(c)                             \
 565   do {                                                  \
 566     if (c > MAX_UNICODE_CHAR && c <= MAX_5_BYTE_CHAR)   \
 567       {                                                 \
 568         Lisp_Object val;                                \
 569         val = CHAR_TABLE_REF (Vchar_unify_table, c);    \
 570         if (INTEGERP (val))                             \
 571           c = XINT (val);                               \
 572         else if (! NILP (val))                          \
 573           c = maybe_unify_char (c, val);                \
 574       }                                                 \
 575   } while (0)
 576
 577
 578 /* Return the width of ASCII character C.  The width is measured by
 579    how many columns C will occupy on the screen when displayed in the
 580    current buffer.  */
 581
 582 #define ASCII_CHAR_WIDTH(c)                                             \
 583   (c < 0x20                                                             \
 584    ? (c == '\t'                                                         \
 585       ? XFASTINT (current_buffer->tab_width)                            \
 586       : (c == '\n' ? 0 : (NILP (current_buffer->ctl_arrow) ? 4 : 2)))   \
 587    : (c < 0x7f                                                          \
 588       ? 1                                                               \
 589       : ((NILP (current_buffer->ctl_arrow) ? 4 : 2))))
 590
 591 /* Return the width of character C.  The width is measured by how many
 592    columns C will occupy on the screen when displayed in the current
 593    buffer.  */
 594
 595 #define CHAR_WIDTH(c)           \
 596   (ASCII_CHAR_P (c)             \
 597    ? ASCII_CHAR_WIDTH (c)       \
 598    : XINT (CHAR_TABLE_REF (Vchar_width_table, c)))
 599
 600 /* If C is a variation selector, return the index numnber of the
 601    variation selector (1..256).  Otherwise, return 0.  */
 602
 603 #define CHAR_VARIATION_SELECTOR_P(c)            \
 604   ((c) < 0xFE00 ? 0                             \
 605    : (c) <= 0xFE0F ? (c) - 0xFE00 + 1           \
 606    : (c) < 0xE0100 ? 0                          \
 607    : (c) <= 0xE01EF ? (c) - 0xE0100 + 17        \
 608    : 0)
 609
 610 /* If C is a high surrogate, return 1.  If C is a low surrogate,
 611    return 0.  Otherwise, return 0.  */
 612
 613 #define CHAR_SURROGATE_PAIR_P(c)        \
 614   ((c) < 0xD800 ? 0                     \
 615    : (c) <= 0xDBFF ? 1                  \
 616    : (c) <= 0xDFFF ? 2                  \
 617    : 0)
 618
 619
 620 extern int char_resolve_modifier_mask P_ ((int));
 621 extern int char_string P_ ((unsigned, unsigned char *));
 622 extern int string_char P_ ((const unsigned char *,
 623                             const unsigned char **, int *));
 624
 625 extern int translate_char P_ ((Lisp_Object, int c));
 626 extern int char_printable_p P_ ((int c));
 627 extern void parse_str_as_multibyte P_ ((const unsigned char *, int, int *,
 628                                         int *));
 629 extern int parse_str_to_multibyte P_ ((unsigned char *, int));
 630 extern int str_as_multibyte P_ ((unsigned char *, int, int, int *));
 631 extern int str_to_multibyte P_ ((unsigned char *, int, int));
 632 extern int str_as_unibyte P_ ((unsigned char *, int));
 633 extern EMACS_INT str_to_unibyte P_ ((const unsigned char *, unsigned char *,
 634                                      EMACS_INT, int));
 635 extern int strwidth P_ ((unsigned char *, int));
 636 extern int c_string_width P_ ((const unsigned char *, int, int, int *, int *));
 637 extern int lisp_string_width P_ ((Lisp_Object, int, int *, int *));
 638
 639 extern Lisp_Object Vprintable_chars;
 640
 641 extern Lisp_Object Qcharacterp, Qauto_fill_chars;
 642 extern Lisp_Object Vtranslation_table_vector;
 643 extern Lisp_Object Vchar_width_table;
 644 extern Lisp_Object Vchar_direction_table;
 645 extern Lisp_Object Vchar_unify_table;
 646 extern Lisp_Object Vunicode_category_table;
 647
 648 extern Lisp_Object string_escape_byte8 P_ ((Lisp_Object));
 649
 650 /* Return a translation table of id number ID.  */
 651 #define GET_TRANSLATION_TABLE(id) \
 652   (XCDR(XVECTOR(Vtranslation_table_vector)->contents[(id)]))
 653
 654 /* A char-table for characters which may invoke auto-filling.  */
 655 extern Lisp_Object Vauto_fill_chars;
 656
 657 extern Lisp_Object Vchar_script_table;
 658 extern Lisp_Object Vscript_representative_chars;
 659
 660 /* Copy LEN bytes from FROM to TO.  This macro should be used only
 661    when a caller knows that LEN is short and the obvious copy loop is
 662    faster than calling bcopy which has some overhead.  Copying a
 663    multibyte sequence of a character is the typical case.  */
 664
 665 #define BCOPY_SHORT(from, to, len)              \
 666   do {                                          \
 667     int i = len;                                \
 668     unsigned char *from_p = from, *to_p = to;   \
 669     while (i--) *to_p++ = *from_p++;            \
 670   } while (0)
 671
 672 #define DEFSYM(sym, name)       \
 673   do { (sym) = intern_c_string ((name)); staticpro (&(sym)); } while (0)
 674
 675 #endif /* EMACS_CHARACTER_H */
 676
 677 /* arch-tag: 4ef86004-2eff-4073-8cea-cfcbcf7188ac
 678    (do not change this comment) */