src/coding.h

   1 /* Header for coding system handler.
   2    Copyright (C) 1995, 1997 Electrotechnical Laboratory, JAPAN.
   3    Licensed to the Free Software Foundation.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs; see the file COPYING.  If not, write to
  19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef _CODING_H
  23 #define _CODING_H
  24
  25 #ifndef _CCL_H
  26 #include "ccl.h"
  27 #endif
  28
  29 /*** EMACS' INTERNAL FORMAT (emacs-mule) section ***/
  30
  31 /* All code (1-byte) of Emacs' internal format is classified into one
  32    of the followings.  See also `charset.h'.  */
  33 enum emacs_code_class_type
  34   {
  35     EMACS_control_code,         /* Control codes in the range
  36                                    0x00..0x1F and 0x7F except for the
  37                                    following two codes.  */
  38     EMACS_linefeed_code,        /* 0x0A (linefeed) to denote
  39                                    end-of-line.  */
  40     EMACS_carriage_return_code, /* 0x0D (carriage-return) to be used
  41                                    in selective display mode.  */
  42     EMACS_ascii_code,           /* ASCII characters.  */
  43     EMACS_leading_code_composition, /* Leading code of a composite
  44                                        character.  */
  45     EMACS_leading_code_2,       /* Base leading code of official
  46                                    TYPE9N character.  */
  47     EMACS_leading_code_3,       /* Base leading code of private TYPE9N
  48                                    or official TYPE9Nx9N character.  */
  49     EMACS_leading_code_4,       /* Base leading code of private
  50                                    TYPE9Nx9N character.  */
  51     EMACS_invalid_code          /* Invalid code, i.e. a base leading
  52                                    code not yet assigned to any
  53                                    charset, or a code of the range
  54                                    0xA0..0xFF.  */
  55   };
  56
  57 extern enum emacs_code_class_type emacs_code_class[256];
  58
  59 /*** ISO2022 section ***/
  60
  61 /* Macros to define code of control characters for ISO2022's functions.  */
  62                         /* code */      /* function */
  63 #define ISO_CODE_LF     0x0A            /* line-feed */
  64 #define ISO_CODE_CR     0x0D            /* carriage-return */
  65 #define ISO_CODE_SO     0x0E            /* shift-out */
  66 #define ISO_CODE_SI     0x0F            /* shift-in */
  67 #define ISO_CODE_SS2_7  0x19            /* single-shift-2 for 7-bit code */
  68 #define ISO_CODE_ESC    0x1B            /* escape */
  69 #define ISO_CODE_SS2    0x8E            /* single-shift-2 */
  70 #define ISO_CODE_SS3    0x8F            /* single-shift-3 */
  71 #define ISO_CODE_CSI    0x9B            /* control-sequence-introduce */
  72
  73 /* All code (1-byte) of ISO2022 is classified into one of the
  74    followings.  */
  75 enum iso_code_class_type
  76   {
  77     ISO_control_code,           /* Control codes in the range
  78                                    0x00..0x1F, 0x7F, and 0x80..0x9F,
  79                                    except for the following seven
  80                                    codes.  */
  81     ISO_carriage_return,        /* ISO_CODE_CR (0x0D) */
  82     ISO_shift_out,              /* ISO_CODE_SO (0x0E) */
  83     ISO_shift_in,               /* ISO_CODE_SI (0x0F) */
  84     ISO_single_shift_2_7,       /* ISO_CODE_SS2_7 (0x19) */
  85     ISO_escape,                 /* ISO_CODE_SO (0x1B) */
  86     ISO_single_shift_2,         /* ISO_CODE_SS2 (0x8E) */
  87     ISO_single_shift_3,         /* ISO_CODE_SS3 (0x8F) */
  88     ISO_control_sequence_introducer, /* ISO_CODE_CSI (0x9B) */
  89     ISO_0x20_or_0x7F,           /* Codes of the values 0x20 or 0x7F.  */
  90     ISO_graphic_plane_0,        /* Graphic codes in the range 0x21..0x7E.  */
  91     ISO_0xA0_or_0xFF,           /* Codes of the values 0xA0 or 0xFF.  */
  92     ISO_graphic_plane_1         /* Graphic codes in the range 0xA1..0xFE.  */
  93   };
  94
  95 /** The macros CODING_FLAG_ISO_XXX defines a flag bit of the `flags'
  96   element in the structure `coding_system'.  This information is used
  97   while encoding a text to ISO2022.  **/
  98
  99 /* If set, produce short-form designation sequence (e.g. ESC $ A)
 100    instead of long-form sequence (e.g. ESC $ ( A).  */
 101 #define CODING_FLAG_ISO_SHORT_FORM      0x0001
 102
 103 /* If set, reset graphic planes and registers at end-of-line to the
 104    initial state.  */
 105 #define CODING_FLAG_ISO_RESET_AT_EOL    0x0002
 106
 107 /* If set, reset graphic planes and registers before any control
 108    characters to the initial state.  */
 109 #define CODING_FLAG_ISO_RESET_AT_CNTL   0x0004
 110
 111 /* If set, encode by 7-bit environment.  */
 112 #define CODING_FLAG_ISO_SEVEN_BITS      0x0008
 113
 114 /* If set, use locking-shift function.  */
 115 #define CODING_FLAG_ISO_LOCKING_SHIFT   0x0010
 116
 117 /* If set, use single-shift function.  Overwrite
 118    CODING_FLAG_ISO_LOCKING_SHIFT.  */
 119 #define CODING_FLAG_ISO_SINGLE_SHIFT    0x0020
 120
 121 /* If set, designate JISX0201-Roman instead of ASCII.  */
 122 #define CODING_FLAG_ISO_USE_ROMAN       0x0040
 123
 124 /* If set, designate JISX0208-1978 instead of JISX0208-1983.  */
 125 #define CODING_FLAG_ISO_USE_OLDJIS      0x0080
 126
 127 /* If set, do not produce ISO6429's direction specifying sequence.  */
 128 #define CODING_FLAG_ISO_NO_DIRECTION    0x0100
 129
 130 /* If set, assume designation states are reset at beginning of line on
 131    output.  */
 132 #define CODING_FLAG_ISO_INIT_AT_BOL     0x0200
 133
 134 /* If set, designation sequence should be placed at beginning of line
 135    on output.  */
 136 #define CODING_FLAG_ISO_DESIGNATE_AT_BOL 0x0400
 137
 138 /* If set, do not encode unsafe charactes on output.  */
 139 #define CODING_FLAG_ISO_SAFE            0x0800
 140
 141 /* If set, extra latin codes (128..159) are accepted as a valid code
 142    on input.  */
 143 #define CODING_FLAG_ISO_LATIN_EXTRA     0x1000
 144
 145 /* If set, use designation escape sequence.  */
 146 #define CODING_FLAG_ISO_DESIGNATION     0x10000
 147
 148 /* A character to be produced on output if encoding of the original
 149    character is prohibited by CODING_FLAG_ISO_SAFE.  */
 150 #define CODING_INHIBIT_CHARACTER_SUBSTITUTION  077 /* 077 == `?' */
 151
 152 /* Structure of the field `spec.iso2022' in the structure `coding_system'.  */
 153 struct iso2022_spec
 154 {
 155   /* The current graphic register invoked to each graphic plane.  */
 156   int current_invocation[2];
 157
 158   /* The current charset designated to each graphic register.  */
 159   int current_designation[4];
 160
 161   /* A charset initially designated to each graphic register.  */
 162   int initial_designation[4];
 163
 164   /* If not -1, it is a graphic register specified in an invalid
 165      designation sequence.  */
 166   int last_invalid_designation_register;
 167
 168   /* A graphic register to which each charset should be designated.  */
 169   unsigned char requested_designation[MAX_CHARSET + 1];
 170
 171   /* A revision number to be specified for each charset on encoding.
 172      The value 255 means no revision number for the corresponding
 173      charset.  */
 174   unsigned char charset_revision_number[MAX_CHARSET + 1];
 175
 176   /* Set to 1 temporarily only when graphic register 2 or 3 is invoked
 177      by single-shift while encoding.  */
 178   int single_shifting;
 179
 180   /* Set to 1 temporarily only when processing at beginning of line.  */
 181   int bol;
 182 };
 183
 184 /* Macros to access each field in the structure `spec.iso2022'.  */
 185 #define CODING_SPEC_ISO_INVOCATION(coding, plane) \
 186   (coding)->spec.iso2022.current_invocation[plane]
 187 #define CODING_SPEC_ISO_DESIGNATION(coding, reg) \
 188   (coding)->spec.iso2022.current_designation[reg]
 189 #define CODING_SPEC_ISO_INITIAL_DESIGNATION(coding, reg) \
 190   (coding)->spec.iso2022.initial_designation[reg]
 191 #define CODING_SPEC_ISO_REQUESTED_DESIGNATION(coding, charset) \
 192   (coding)->spec.iso2022.requested_designation[charset]
 193 #define CODING_SPEC_ISO_REVISION_NUMBER(coding, charset) \
 194   (coding)->spec.iso2022.charset_revision_number[charset]
 195 #define CODING_SPEC_ISO_SINGLE_SHIFTING(coding) \
 196   (coding)->spec.iso2022.single_shifting
 197 #define CODING_SPEC_ISO_BOL(coding) \
 198   (coding)->spec.iso2022.bol
 199
 200 /* A value which may appear in
 201    coding->spec.iso2022.requested_designation indicating that the
 202    corresponding charset does not request any graphic register to be
 203    designated.  */
 204 #define CODING_SPEC_ISO_NO_REQUESTED_DESIGNATION 4
 205
 206 /* Return a charset which is currently designated to the graphic plane
 207    PLANE in the coding-system CODING.  */
 208 #define CODING_SPEC_ISO_PLANE_CHARSET(coding, plane)    \
 209   ((CODING_SPEC_ISO_INVOCATION (coding, plane) < 0)     \
 210    ? -1                                                 \
 211    : CODING_SPEC_ISO_DESIGNATION (coding,               \
 212                                   CODING_SPEC_ISO_INVOCATION (coding, plane)))
 213
 214 /*** BIG5 section ***/
 215
 216 /* Macros to denote each type of BIG5 coding system.  */
 217 #define CODING_FLAG_BIG5_HKU    0x00 /* BIG5-HKU is one of variants of
 218                                         BIG5 developed by Hong Kong
 219                                         University.  */
 220 #define CODING_FLAG_BIG5_ETEN   0x01 /* BIG5_ETen is one of variants
 221                                         of BIG5 developed by the
 222                                         company ETen in Taiwan.  */
 223
 224 /*** GENERAL section ***/
 225
 226 /* Types of coding system.  */
 227 enum coding_type
 228   {
 229     coding_type_no_conversion,  /* A coding system which requires no
 230                                    conversion for reading and writing
 231                                    including end-of-line format.  */
 232     coding_type_emacs_mule,     /* A coding system used in Emacs'
 233                                    buffer and string.  Requires no
 234                                    conversion for reading and writing
 235                                    except for end-of-line format.  */
 236     coding_type_undecided,      /* A coding system which requires
 237                                    automatic detection of a real
 238                                    coding system.  */
 239     coding_type_sjis,           /* SJIS coding system for Japanese.  */
 240     coding_type_iso2022,        /* Any coding system of ISO2022
 241                                    variants.  */
 242     coding_type_big5,           /* BIG5 coding system for Chinese.  */
 243     coding_type_ccl,            /* The coding system of which decoder
 244                                    and encoder are written in CCL.  */
 245     coding_type_raw_text        /* A coding system for a text
 246                                    containing ramdom 8-bit code which
 247                                    does not require code conversion
 248                                    except for end-of-line format. */
 249   };
 250
 251 /* Formats of end-of-line.  */
 252 #define CODING_EOL_LF   0       /* Line-feed only, same as Emacs'
 253                                    internal format.  */
 254 #define CODING_EOL_CRLF 1       /* Sequence of carriage-return and
 255                                    line-feed.  */
 256 #define CODING_EOL_CR   2       /* Carriage-return only.  */
 257 #define CODING_EOL_UNDECIDED 3  /* This value is used to denote the
 258                                    eol-type is not yet decided.  */
 259 #define CODING_EOL_INCONSISTENT 4 /* This value is used to denote the
 260                                      eol-type is not consistent
 261                                      through the file.  */
 262
 263 /* Character composition status while encoding/decoding.  */
 264 #define COMPOSING_NO             0 /* not composing */
 265 #define COMPOSING_WITH_RULE_HEAD 1 /* 1st char of with-rule composing follow */
 266 #define COMPOSING_NO_RULE_HEAD   2 /* 1st char of no-rule composing follow */
 267 #define COMPOSING_WITH_RULE_TAIL 3 /* Nth char of with-rule composing follow */
 268 #define COMPOSING_NO_RULE_TAIL   4 /* Nth char of no-rule composing follow */
 269 #define COMPOSING_WITH_RULE_RULE 5 /* composition rule follow */
 270
 271 /* 1 iff composing.  */
 272 #define COMPOSING_P(composing) (composing)
 273 /* 1 iff 1st char of composing element follows.  */
 274 #define COMPOSING_HEAD_P(composing) \
 275   ((composing) && (composing) <= COMPOSING_NO_RULE_HEAD)
 276 /* 1 iff composing with embeded composition rule.  */
 277 #define COMPOSING_WITH_RULE_P(composing) ((composing) & 1)
 278
 279 /* Macros used for the member finish_status of the struct
 280    coding_system.  */
 281 #define CODING_FINISH_NORMAL            0
 282 #define CODING_FINISH_INSUFFICIENT_SRC  1
 283 #define CODING_FINISH_INSUFFICIENT_DST  2
 284 #define CODING_FINISH_INCONSISTENT_EOL  3
 285 #define CODING_FINISH_INTERRUPT         4
 286
 287 /* Macros used for the member `mode' of the struct coding_system.  */
 288
 289 /* If set, recover the original CR or LF of the already decoded text
 290    when the decoding routine encounters an inconsistent eol format.  */
 291 #define CODING_MODE_INHIBIT_INCONSISTENT_EOL    0x01
 292
 293 /* If set, the decoding/encoding routines treat the current data as
 294    the last block of the whole text to be converted, and do
 295    appropriate fisishing job.  */
 296 #define CODING_MODE_LAST_BLOCK                  0x02
 297
 298 /* If set, it means that the current source text is in a buffer which
 299    enables selective display.  */
 300 #define CODING_MODE_SELECTIVE_DISPLAY           0x04
 301
 302 /* This flag is used by the decoding/encoding routines on the fly.  If
 303    set, it means that right-to-left text is being processed.  */
 304 #define CODING_MODE_DIRECTION                   0x08
 305
 306 struct coding_system
 307 {
 308   /* Type of the coding system.  */
 309   enum coding_type type;
 310
 311   /* Type of end-of-line format (LF, CRLF, or CR) of the coding system.  */
 312   int eol_type;
 313
 314   /* Flag bits of the coding system.  The meaning of each bit is common
 315      to all types of coding systems.  */
 316   unsigned int common_flags;
 317
 318   /* Flag bits of the coding system.  The meaning of each bit depends
 319      on the type of the coding system.  */
 320   unsigned int flags;
 321
 322   /* Mode bits of the coding system.  See the comments of the macros
 323      CODING_MODE_XXX.  */
 324   unsigned int mode;
 325
 326   /* Table of safe character sets for this coding system.  If the Nth
 327      element is 0, the charset of ID N is not a safe character set.
 328      Such a character set is not encoded when CODING_ISO_FLAG_SAFE is
 329      set.  */
 330   unsigned char safe_charsets[MAX_CHARSET + 1];
 331
 332   /* Non-zero means that characters are being composed currently while
 333      decoding or encoding.  See macros COMPOSING_XXXX above for the
 334      meaing of each non-zero value.  */
 335   int composing;
 336
 337   /* Number of composed characters in the current composing sequence.  */
 338   int composed_chars;
 339
 340   /* Detailed information specific to each type of coding system.  */
 341   union spec
 342     {
 343       struct iso2022_spec iso2022;
 344       struct ccl_spec ccl;      /* Defined in ccl.h.  */
 345     } spec;
 346
 347   /* Index number of coding category of the coding system.  */
 348   int category_idx;
 349
 350   /* How may heading bytes we can skip for decoding.  This is set to
 351      -1 in setup_coding_system, and updated by detect_coding.  So,
 352      when this is equal to the byte length of the text being
 353      converted, we can skip the actual conversion process.  */
 354   int heading_ascii;
 355
 356   /* The following members are set by encoding/decoding routine.  */
 357   int produced, produced_char, consumed, consumed_char;
 358
 359   /* Encoding routines set this to 1 when they produce a byte sequence
 360      which can be parsed as a multibyte character.  Decoding routines
 361      set this to 1 when they encounter an invalid code and, as the
 362      result, produce an unexpected multibyte character.  */
 363   int fake_multibyte;
 364
 365   /* The following members are all Lisp symbols.  We don't have to
 366      protect them from GC because the current garbage collection
 367      doesn't relocate Lisp symbols.  But, when it is changed, we must
 368      find a way to protect them.  */
 369
 370   /* Backward pointer to the Lisp symbol of the coding system.  */
 371   Lisp_Object symbol;
 372
 373   /* Lisp function (symbol) to be called after decoding to do
 374      additional conversion, or nil.  */
 375   Lisp_Object post_read_conversion;
 376
 377   /* Lisp function (symbol) to be called before encoding to do
 378      additional conversion, or nil.  */
 379   Lisp_Object pre_write_conversion;
 380
 381   /* Character translation tables to look up, or nil.  */
 382   Lisp_Object translation_table_for_decode;
 383   Lisp_Object translation_table_for_encode;
 384 };
 385
 386 #define CODING_REQUIRE_FLUSHING_MASK    1
 387 #define CODING_REQUIRE_DECODING_MASK    2
 388 #define CODING_REQUIRE_ENCODING_MASK    4
 389 #define CODING_REQUIRE_DETECTION_MASK   8
 390
 391 /* Return 1 if the coding system CODING requires specific code to be
 392    attached at the tail of converted text.  */
 393 #define CODING_REQUIRE_FLUSHING(coding) \
 394   ((coding)->common_flags & CODING_REQUIRE_FLUSHING_MASK)
 395
 396 /* Return 1 if the coding system CODING requires code conversion on
 397    decoding.  */
 398 #define CODING_REQUIRE_DECODING(coding) \
 399   ((coding)->common_flags & CODING_REQUIRE_DECODING_MASK)
 400
 401 /* Return 1 if the coding system CODING requires code conversion on
 402    encoding.  */
 403 #define CODING_REQUIRE_ENCODING(coding) \
 404   ((coding)->common_flags & CODING_REQUIRE_ENCODING_MASK)
 405
 406 /* Return 1 if the coding system CODING requires some kind of code
 407    detection.  */
 408 #define CODING_REQUIRE_DETECTION(coding) \
 409   ((coding)->common_flags & CODING_REQUIRE_DETECTION_MASK)
 410
 411 #define CODING_MAY_REQUIRE_DECODING(coding)     \
 412   ((coding)->common_flags                       \
 413    & (CODING_REQUIRE_DETECTION_MASK | CODING_REQUIRE_DECODING_MASK))
 414
 415 /* Index for each coding category in `coding_category_table' */
 416 #define CODING_CATEGORY_IDX_EMACS_MULE  0
 417 #define CODING_CATEGORY_IDX_SJIS        1
 418 #define CODING_CATEGORY_IDX_ISO_7       2
 419 #define CODING_CATEGORY_IDX_ISO_7_TIGHT 3
 420 #define CODING_CATEGORY_IDX_ISO_8_1     4
 421 #define CODING_CATEGORY_IDX_ISO_8_2     5
 422 #define CODING_CATEGORY_IDX_ISO_7_ELSE  6
 423 #define CODING_CATEGORY_IDX_ISO_8_ELSE  7
 424 #define CODING_CATEGORY_IDX_CCL         8
 425 #define CODING_CATEGORY_IDX_BIG5        9
 426 #define CODING_CATEGORY_IDX_RAW_TEXT    10
 427 #define CODING_CATEGORY_IDX_BINARY      11
 428 #define CODING_CATEGORY_IDX_MAX         12
 429
 430 /* Definitions of flag bits returned by the function
 431    detect_coding_mask ().  */
 432 #define CODING_CATEGORY_MASK_EMACS_MULE (1 << CODING_CATEGORY_IDX_EMACS_MULE)
 433 #define CODING_CATEGORY_MASK_SJIS       (1 << CODING_CATEGORY_IDX_SJIS)
 434 #define CODING_CATEGORY_MASK_ISO_7      (1 << CODING_CATEGORY_IDX_ISO_7)
 435 #define CODING_CATEGORY_MASK_ISO_7_TIGHT (1 << CODING_CATEGORY_IDX_ISO_7_TIGHT)
 436 #define CODING_CATEGORY_MASK_ISO_8_1    (1 << CODING_CATEGORY_IDX_ISO_8_1)
 437 #define CODING_CATEGORY_MASK_ISO_8_2    (1 << CODING_CATEGORY_IDX_ISO_8_2)
 438 #define CODING_CATEGORY_MASK_ISO_7_ELSE (1 << CODING_CATEGORY_IDX_ISO_7_ELSE)
 439 #define CODING_CATEGORY_MASK_ISO_8_ELSE (1 << CODING_CATEGORY_IDX_ISO_8_ELSE)
 440 #define CODING_CATEGORY_MASK_CCL        (1 << CODING_CATEGORY_IDX_CCL)
 441 #define CODING_CATEGORY_MASK_BIG5       (1 << CODING_CATEGORY_IDX_BIG5)
 442 #define CODING_CATEGORY_MASK_RAW_TEXT   (1 << CODING_CATEGORY_IDX_RAW_TEXT)
 443 #define CODING_CATEGORY_MASK_BINARY     (1 << CODING_CATEGORY_IDX_BINARY)
 444
 445 /* This value is returned if detect_coding_mask () find nothing other
 446    than ASCII characters.  */
 447 #define CODING_CATEGORY_MASK_ANY        \
 448   (  CODING_CATEGORY_MASK_EMACS_MULE    \
 449    | CODING_CATEGORY_MASK_SJIS          \
 450    | CODING_CATEGORY_MASK_ISO_7         \
 451    | CODING_CATEGORY_MASK_ISO_7_TIGHT   \
 452    | CODING_CATEGORY_MASK_ISO_8_1       \
 453    | CODING_CATEGORY_MASK_ISO_8_2       \
 454    | CODING_CATEGORY_MASK_ISO_7_ELSE    \
 455    | CODING_CATEGORY_MASK_ISO_8_ELSE    \
 456    | CODING_CATEGORY_MASK_CCL           \
 457    | CODING_CATEGORY_MASK_BIG5)
 458
 459 #define CODING_CATEGORY_MASK_ISO_7BIT \
 460   (CODING_CATEGORY_MASK_ISO_7 | CODING_CATEGORY_MASK_ISO_7_TIGHT)
 461
 462 #define CODING_CATEGORY_MASK_ISO_8BIT \
 463   (CODING_CATEGORY_MASK_ISO_8_1 | CODING_CATEGORY_MASK_ISO_8_2)
 464
 465 #define CODING_CATEGORY_MASK_ISO_SHIFT \
 466   (CODING_CATEGORY_MASK_ISO_7_ELSE | CODING_CATEGORY_MASK_ISO_8_ELSE)
 467
 468 #define CODING_CATEGORY_MASK_ISO        \
 469   (  CODING_CATEGORY_MASK_ISO_7BIT      \
 470    | CODING_CATEGORY_MASK_ISO_SHIFT     \
 471    | CODING_CATEGORY_MASK_ISO_8BIT)
 472
 473 /* Macros to decode or encode a character of JISX0208 in SJIS.  S1 and
 474    S2 are the 1st and 2nd position-codes of JISX0208 in SJIS coding
 475    system.  C1 and C2 are the 1st and 2nd position codes of Emacs'
 476    internal format.  */
 477
 478 #define DECODE_SJIS(s1, s2, c1, c2)                     \
 479   do {                                                  \
 480     if (s2 >= 0x9F)                                     \
 481       c1 = s1 * 2 - (s1 >= 0xE0 ? 0x160 : 0xE0),        \
 482       c2 = s2 - 0x7E;                                   \
 483     else                                                \
 484       c1 = s1 * 2 - ((s1 >= 0xE0) ? 0x161 : 0xE1),      \
 485       c2 = s2 - ((s2 >= 0x7F) ? 0x20 : 0x1F);           \
 486   } while (0)
 487
 488 #define ENCODE_SJIS(c1, c2, s1, s2)                     \
 489   do {                                                  \
 490     if (c1 & 1)                                         \
 491       s1 = c1 / 2 + ((c1 < 0x5F) ? 0x71 : 0xB1),        \
 492       s2 = c2 + ((c2 >= 0x60) ? 0x20 : 0x1F);           \
 493     else                                                \
 494       s1 = c1 / 2 + ((c1 < 0x5F) ? 0x70 : 0xB0),        \
 495       s2 = c2 + 0x7E;                                   \
 496   } while (0)
 497
 498 /* Encode the file name NAME using the specified coding system
 499    for file names, if any.  */
 500 #define ENCODE_FILE(name)                                                  \
 501   (! NILP (Vfile_name_coding_system)                                       \
 502    && XFASTINT (Vfile_name_coding_system) != 0                             \
 503    ? code_convert_string_norecord (name, Vfile_name_coding_system, 1)      \
 504    : (! NILP (Vdefault_file_name_coding_system)                            \
 505       && XFASTINT (Vdefault_file_name_coding_system) != 0                  \
 506       ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 1) \
 507       : name))
 508
 509 /* Decode the file name NAME using the specified coding system
 510    for file names, if any.  */
 511 #define DECODE_FILE(name)                                                  \
 512   (! NILP (Vfile_name_coding_system)                                       \
 513    && XFASTINT (Vfile_name_coding_system) != 0                             \
 514    ? code_convert_string_norecord (name, Vfile_name_coding_system, 0)      \
 515    : (! NILP (Vdefault_file_name_coding_system)                            \
 516       && XFASTINT (Vdefault_file_name_coding_system) != 0                  \
 517       ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 0) \
 518       : name))
 519
 520 /* Extern declarations.  */
 521 extern int decode_coding P_ ((struct coding_system *, unsigned char *,
 522                               unsigned char *, int, int));
 523 extern int encode_coding P_ ((struct coding_system *, unsigned char *,
 524                               unsigned char *, int, int));
 525 extern int code_convert_region P_ ((int, int, int, int, struct coding_system *,
 526                                     int, int));
 527 extern int decoding_buffer_size P_ ((struct coding_system *, int));
 528 extern int encoding_buffer_size P_ ((struct coding_system *, int));
 529 extern void detect_coding P_ ((struct coding_system *, unsigned char *, int));
 530 extern void detect_eol P_ ((struct coding_system *, unsigned char *, int));
 531 extern int conversion_buffer_size;
 532 extern char *conversion_buffer;
 533 extern char *get_conversion_buffer P_ ((int));
 534 extern int setup_coding_system P_ ((Lisp_Object, struct coding_system *));
 535 extern void setup_raw_text_coding_system P_ ((struct coding_system *));
 536 extern Lisp_Object Qcoding_system, Qeol_type, Qcoding_category_index;
 537 extern Lisp_Object Qraw_text, Qemacs_mule;
 538 extern Lisp_Object Qbuffer_file_coding_system;
 539 extern Lisp_Object Vcoding_category_list;
 540
 541 extern Lisp_Object Qtranslation_table;
 542 extern Lisp_Object Qtranslation_table_id;
 543
 544 /* Mnemonic strings to indicate each type of end-of-line.  */
 545 extern Lisp_Object eol_mnemonic_unix, eol_mnemonic_dos, eol_mnemonic_mac;
 546 /* Mnemonic string to indicate type of end-of-line is not yet decided.  */
 547 extern Lisp_Object eol_mnemonic_undecided;
 548
 549 #ifdef emacs
 550 extern Lisp_Object Qfile_coding_system;
 551 extern Lisp_Object Qcall_process, Qcall_process_region, Qprocess_argument;
 552 extern Lisp_Object Qstart_process, Qopen_network_stream;
 553
 554 extern char *emacs_strerror P_ ((int));
 555
 556 /* Coding-system for reading files and receiving data from process.  */
 557 extern Lisp_Object Vcoding_system_for_read;
 558 /* Coding-system for writing files and sending data to process.  */
 559 extern Lisp_Object Vcoding_system_for_write;
 560 /* Coding-system actually used in the latest I/O.  */
 561 extern Lisp_Object Vlast_coding_system_used;
 562 /* Coding-system to use with system messages (e.g. strerror).  */
 563 extern Lisp_Object Vlocale_coding_system;
 564
 565 /* If non-zero, process buffer inherits the coding system used to decode
 566    the subprocess output.  */
 567 extern int inherit_process_coding_system;
 568
 569 /* Coding-system to be used for encoding terminal output.  This
 570    structure contains information of a coding-system specified by the
 571    function `set-terminal-coding-system'.  */
 572 extern struct coding_system terminal_coding;
 573
 574 /* Coding system to be used to encode text for terminal display when
 575    terminal coding system is nil.  */
 576 extern struct coding_system safe_terminal_coding;
 577
 578 /* Coding-system of what is sent from terminal keyboard.  This
 579    structure contains information of a coding-system specified by the
 580    function `set-keyboard-coding-system'.  */
 581 extern struct coding_system keyboard_coding;
 582
 583 /* Default coding system to be used to write a file.  */
 584 extern struct coding_system default_buffer_file_coding;
 585
 586 /* Default coding systems used for process I/O.  */
 587 extern Lisp_Object Vdefault_process_coding_system;
 588
 589 /* Function to call to force a user to force select a propert coding
 590    system.  */
 591 extern Lisp_Object Vselect_safe_coding_system_function;
 592
 593 /* Coding system for file names, or nil if none.  */
 594 extern Lisp_Object Vfile_name_coding_system;
 595
 596 /* Coding system for file names used only when
 597    Vfile_name_coding_system is nil.  */
 598 extern Lisp_Object Vdefault_file_name_coding_system;
 599 #endif
 600
 601 #endif /* _CODING_H */