Completely re-written.

1 files changed, 402 insertions, 457 deletions

diff --git a/src/coding.h b/src/coding.h
index 500f02acf32..cc115b6ef3f 100644
--- a/src/coding.h
+++ b/src/coding.h
@@ -1,6 +1,9 @@
 /* Header for coding system handler.
    Copyright (C) 1995, 1997 Electrotechnical Laboratory, JAPAN.
    Licensed to the Free Software Foundation.
+   Copyright (C) 2001, 2002
+     National Institute of Advanced Industrial Science and Technology (AIST)
+     Registration Number H13PRO009
 
 This file is part of GNU Emacs.
 
@@ -22,305 +25,203 @@ Boston, MA 02111-1307, USA.  */
 #ifndef EMACS_CODING_H
 #define EMACS_CODING_H
 
-#include "ccl.h"
+/* Index to arguments of Fdefine_coding_system_internal.  */
 
-/*** EMACS' INTERNAL FORMAT (emacs-mule) section ***/
+enum define_coding_system_arg_index
+  {
+    coding_arg_name,
+    coding_arg_mnemonic,
+    coding_arg_coding_type,
+    coding_arg_charset_list,
+    coding_arg_ascii_compatible_p,
+    coding_arg_decode_translation_table,
+    coding_arg_encode_translation_table,
+    coding_arg_post_read_conversion,
+    coding_arg_pre_write_conversion,
+    coding_arg_default_char,
+    coding_arg_plist,
+    coding_arg_eol_type,
+    coding_arg_max
+  };
 
-/* All code (1-byte) of Emacs' internal format is classified into one
-   of the followings.  See also `charset.h'.  */
-enum emacs_code_class_type
+enum define_coding_iso2022_arg_index
   {
-    EMACS_control_code,         /* Control codes in the range
-                                   0x00..0x1F and 0x7F except for the
-                                   following two codes.  */
-    EMACS_linefeed_code,        /* 0x0A (linefeed) to denote
-                                   end-of-line.  */
-    EMACS_carriage_return_code, /* 0x0D (carriage-return) to be used
-                                   in selective display mode.  */
-    EMACS_ascii_code,           /* ASCII characters.  */
-    EMACS_leading_code_2,       /* Base leading code of official
-                                   TYPE9N character.  */
-    EMACS_leading_code_3,       /* Base leading code of private TYPE9N
-                                   or official TYPE9Nx9N character.  */
-    EMACS_leading_code_4,       /* Base leading code of private
-                                   TYPE9Nx9N character.  */
-    EMACS_invalid_code          /* Invalid code, i.e. a base leading
-                                   code not yet assigned to any
-                                   charset, or a code of the range
-                                   0xA0..0xFF.  */
+    coding_arg_iso2022_initial = coding_arg_max,
+    coding_arg_iso2022_reg_usage,
+    coding_arg_iso2022_request,
+    coding_arg_iso2022_flags,
+    coding_arg_iso2022_max
   };
 
-extern enum emacs_code_class_type emacs_code_class[256];
-
-/*** ISO2022 section ***/
-
-/* Macros to define code of control characters for ISO2022's functions.  */
-                        /* code */      /* function */
-#define ISO_CODE_LF     0x0A            /* line-feed */
-#define ISO_CODE_CR     0x0D            /* carriage-return */
-#define ISO_CODE_SO     0x0E            /* shift-out */
-#define ISO_CODE_SI     0x0F            /* shift-in */
-#define ISO_CODE_SS2_7  0x19            /* single-shift-2 for 7-bit code */
-#define ISO_CODE_ESC    0x1B            /* escape */
-#define ISO_CODE_SS2    0x8E            /* single-shift-2 */
-#define ISO_CODE_SS3    0x8F            /* single-shift-3 */
-#define ISO_CODE_CSI    0x9B            /* control-sequence-introduce */
-
-/* All code (1-byte) of ISO2022 is classified into one of the
-   followings.  */
-enum iso_code_class_type
+enum define_coding_utf16_arg_index
   {
-    ISO_control_0,              /* Control codes in the range
-                                   0x00..0x1F and 0x7F, except for the
-                                   following 5 codes.  */
-    ISO_carriage_return,        /* ISO_CODE_CR (0x0D) */
-    ISO_shift_out,              /* ISO_CODE_SO (0x0E) */
-    ISO_shift_in,               /* ISO_CODE_SI (0x0F) */
-    ISO_single_shift_2_7,       /* ISO_CODE_SS2_7 (0x19) */
-    ISO_escape,                 /* ISO_CODE_SO (0x1B) */
-    ISO_control_1,              /* Control codes in the range
-                                   0x80..0x9F, except for the
-                                   following 3 codes.  */
-    ISO_single_shift_2,         /* ISO_CODE_SS2 (0x8E) */
-    ISO_single_shift_3,         /* ISO_CODE_SS3 (0x8F) */
-    ISO_control_sequence_introducer, /* ISO_CODE_CSI (0x9B) */
-    ISO_0x20_or_0x7F,           /* Codes of the values 0x20 or 0x7F.  */
-    ISO_graphic_plane_0,        /* Graphic codes in the range 0x21..0x7E.  */
-    ISO_0xA0_or_0xFF,           /* Codes of the values 0xA0 or 0xFF.  */
-    ISO_graphic_plane_1         /* Graphic codes in the range 0xA1..0xFE.  */
+    coding_arg_utf16_bom = coding_arg_max,
+    coding_arg_utf16_endian,
+    coding_arg_utf16_max
   };
 
-/** The macros CODING_FLAG_ISO_XXX defines a flag bit of the `flags'
-  element in the structure `coding_system'.  This information is used
-  while encoding a text to ISO2022.  **/
+enum define_coding_ccl_arg_index
+  {
+    coding_arg_ccl_decoder,
+    coding_arg_ccl_encoder,
+    coding_arg_ccl_valids,
+    coding_arg_ccl_max
+  };
 
-/* If set, produce short-form designation sequence (e.g. ESC $ A)
-   instead of long-form sequence (e.g. ESC $ ( A).  */
-#define CODING_FLAG_ISO_SHORT_FORM      0x0001
+extern Lisp_Object Vcoding_system_hash_table;
 
-/* If set, reset graphic planes and registers at end-of-line to the
-   initial state.  */
-#define CODING_FLAG_ISO_RESET_AT_EOL    0x0002
+/* Enumeration of coding system type.  */
 
-/* If set, reset graphic planes and registers before any control
-   characters to the initial state.  */
-#define CODING_FLAG_ISO_RESET_AT_CNTL   0x0004
+enum coding_system_type
+  {
+    coding_type_charset,
+    coding_type_utf_8,
+    coding_type_utf_16,
+    coding_type_iso_2022,
+    coding_type_emacs_mule,
+    coding_type_sjis,
+    coding_type_ccl,
+    coding_type_raw_text,
+    coding_type_undecided,
+    coding_type_max
+  };
 
-/* If set, encode by 7-bit environment.  */
-#define CODING_FLAG_ISO_SEVEN_BITS      0x0008
 
-/* If set, use locking-shift function.  */
-#define CODING_FLAG_ISO_LOCKING_SHIFT   0x0010
+/* Enumeration of end-of-line format type.  */
 
-/* If set, use single-shift function.  Overwrite
-   CODING_FLAG_ISO_LOCKING_SHIFT.  */
-#define CODING_FLAG_ISO_SINGLE_SHIFT    0x0020
+enum end_of_line_type
+  {
+    eol_lf,             /* Line-feed only, same as Emacs' internal
+                           format.  */
+    eol_crlf,           /* Sequence of carriage-return and
+                           line-feed.  */
+    eol_cr,             /* Carriage-return only.  */
+    eol_any,            /* Accept any of above.  Produce line-feed
+                           only.  */
+    eol_undecided,      /* This value is used to denote that the
+                           eol-type is not yet undecided.  */
+    eol_type_max
+  };
 
-/* If set, designate JISX0201-Roman instead of ASCII.  */
-#define CODING_FLAG_ISO_USE_ROMAN       0x0040
+/* Enumeration of index to an attribute vector of a coding system.  */
 
-/* If set, designate JISX0208-1978 instead of JISX0208-1983.  */
-#define CODING_FLAG_ISO_USE_OLDJIS      0x0080
+enum coding_attr_index
+  {
+    coding_attr_base_name,
+    coding_attr_docstring,
+    coding_attr_mnemonic,
+    coding_attr_type,
+    coding_attr_charset_list,
+    coding_attr_ascii_compat,
+    coding_attr_decode_tbl,
+    coding_attr_encode_tbl,
+    coding_attr_post_read,
+    coding_attr_pre_write,
+    coding_attr_default_char,
+    coding_attr_plist,
+
+    coding_attr_category,
+    coding_attr_safe_charsets,
+
+    /* The followings are extra attributes for each type.  */
+    coding_attr_charset_valids,
+
+    coding_attr_ccl_decoder,
+    coding_attr_ccl_encoder,
+    coding_attr_ccl_valids,
+
+    coding_attr_iso_initial,
+    coding_attr_iso_usage,
+    coding_attr_iso_request,
+    coding_attr_iso_flags,
+
+    coding_attr_utf_16_bom,
+    coding_attr_utf_16_endian,
+
+    coding_attr_emacs_mule_full,
+
+    coding_attr_last_index
+  };
 
-/* If set, do not produce ISO6429's direction specifying sequence.  */
-#define CODING_FLAG_ISO_NO_DIRECTION    0x0100
 
-/* If set, assume designation states are reset at beginning of line on
-   output.  */
-#define CODING_FLAG_ISO_INIT_AT_BOL     0x0200
+#define CODING_ATTR_BASE_NAME(attrs)    AREF (attrs, coding_attr_base_name)
+#define CODING_ATTR_TYPE(attrs)         AREF (attrs, coding_attr_type)
+#define CODING_ATTR_CHARSET_LIST(attrs) AREF (attrs, coding_attr_charset_list)
+#define CODING_ATTR_MNEMONIC(attrs)     AREF (attrs, coding_attr_mnemonic)
+#define CODING_ATTR_DOCSTRING(attrs)    AREF (attrs, coding_attr_docstring)
+#define CODING_ATTR_ASCII_COMPAT(attrs) AREF (attrs, coding_attr_ascii_compat)
+#define CODING_ATTR_DECODE_TBL(attrs)   AREF (attrs, coding_attr_decode_tbl)
+#define CODING_ATTR_ENCODE_TBL(attrs)   AREF (attrs, coding_attr_encode_tbl)
+#define CODING_ATTR_POST_READ(attrs)    AREF (attrs, coding_attr_post_read)
+#define CODING_ATTR_PRE_WRITE(attrs)    AREF (attrs, coding_attr_pre_write)
+#define CODING_ATTR_DEFAULT_CHAR(attrs) AREF (attrs, coding_attr_default_char)
+#define CODING_ATTR_DIRECTION(attrs)    AREF (attrs, coding_attr_direction)
+#define CODING_ATTR_FLUSHING(attrs)     AREF (attrs, coding_attr_flushing)
+#define CODING_ATTR_PLIST(attrs)        AREF (attrs, coding_attr_plist)
+#define CODING_ATTR_CATEGORY(attrs)     AREF (attrs, coding_attr_category)
+#define CODING_ATTR_SAFE_CHARSETS(attrs)AREF (attrs, coding_attr_safe_charsets)
 
-/* If set, designation sequence should be placed at beginning of line
-   on output.  */
-#define CODING_FLAG_ISO_DESIGNATE_AT_BOL 0x0400
 
-/* If set, do not encode unsafe characters on output.  */
-#define CODING_FLAG_ISO_SAFE            0x0800
+#define CODING_ID_ATTRS(id)     \
+  (AREF (HASH_VALUE (XHASH_TABLE (Vcoding_system_hash_table), id), 0))
 
-/* If set, extra latin codes (128..159) are accepted as a valid code
-   on input.  */
-#define CODING_FLAG_ISO_LATIN_EXTRA     0x1000
+#define CODING_ID_ALIASES(id)   \
+  (AREF (HASH_VALUE (XHASH_TABLE (Vcoding_system_hash_table), id), 1))
 
-/* If set, use designation escape sequence.  */
-#define CODING_FLAG_ISO_DESIGNATION     0x10000
+#define CODING_ID_EOL_TYPE(id)  \
+  (AREF (HASH_VALUE (XHASH_TABLE (Vcoding_system_hash_table), id), 2))
 
-/* A character to be produced on output if encoding of the original
-   character is prohibited by CODING_FLAG_ISO_SAFE.  */
-#define CODING_INHIBIT_CHARACTER_SUBSTITUTION  077 /* 077 == `?' */
+#define CODING_ID_NAME(id) \
+  (HASH_KEY (XHASH_TABLE (Vcoding_system_hash_table), id))
 
-/* Structure of the field `spec.iso2022' in the structure `coding_system'.  */
-struct iso2022_spec
-{
-  /* The current graphic register invoked to each graphic plane.  */
-  int current_invocation[2];
+#define CODING_SYSTEM_SPEC(coding_system_symbol)        \
+  (Fgethash (coding_system_symbol, Vcoding_system_hash_table, Qnil))
 
-  /* The current charset designated to each graphic register.  */
-  int current_designation[4];
+#define CODING_SYSTEM_ID(coding_system_symbol)                  \
+  hash_lookup (XHASH_TABLE (Vcoding_system_hash_table),         \
+               coding_system_symbol, NULL)
 
-  /* A charset initially designated to each graphic register.  */
-  int initial_designation[4];
+#define CODING_SYSTEM_P(coding_system_symbol)   \
+  (! NILP (CODING_SYSTEM_SPEC (coding_system_symbol)))
 
-  /* If not -1, it is a graphic register specified in an invalid
-     designation sequence.  */
-  int last_invalid_designation_register;
+#define  CHECK_CODING_SYSTEM(x)                         \
+  do {                                                  \
+    if (!CODING_SYSTEM_P (x))                           \
+      x = wrong_type_argument (Qcoding_system_p, (x));  \
+  } while (0)
 
-  /* A graphic register to which each charset should be designated.  */
-  unsigned char requested_designation[MAX_CHARSET + 1];
 
-  /* A revision number to be specified for each charset on encoding.
-     The value 255 means no revision number for the corresponding
-     charset.  */
-  unsigned char charset_revision_number[MAX_CHARSET + 1];
+#define CHECK_CODING_SYSTEM_GET_SPEC(x, spec)           \
+  do {                                                  \
+    spec = CODING_SYSTEM_SPEC (x);                      \
+    if (NILP (spec))                                    \
+      x = wrong_type_argument (Qcoding_system_p, (x));  \
+  } while (0)
 
-  /* Set to 1 temporarily only when graphic register 2 or 3 is invoked
-     by single-shift while encoding.  */
-  int single_shifting;
 
-  /* Set to 1 temporarily only when processing at beginning of line.  */
-  int bol;
-};
+#define CHECK_CODING_SYSTEM_GET_ID(x, id)                       \
+  do                                                            \
+    {                                                           \
+      id = CODING_SYSTEM_ID (x);                                \
+      if (id < 0)                                               \
+        x = wrong_type_argument (Qcoding_system_p, (x));        \
+    } while (0)
 
-/* Macros to access each field in the structure `spec.iso2022'.  */
-#define CODING_SPEC_ISO_INVOCATION(coding, plane) \
-  (coding)->spec.iso2022.current_invocation[plane]
-#define CODING_SPEC_ISO_DESIGNATION(coding, reg) \
-  (coding)->spec.iso2022.current_designation[reg]
-#define CODING_SPEC_ISO_INITIAL_DESIGNATION(coding, reg) \
-  (coding)->spec.iso2022.initial_designation[reg]
-#define CODING_SPEC_ISO_REQUESTED_DESIGNATION(coding, charset) \
-  (coding)->spec.iso2022.requested_designation[charset]
-#define CODING_SPEC_ISO_REVISION_NUMBER(coding, charset) \
-  (coding)->spec.iso2022.charset_revision_number[charset]
-#define CODING_SPEC_ISO_SINGLE_SHIFTING(coding) \
-  (coding)->spec.iso2022.single_shifting
-#define CODING_SPEC_ISO_BOL(coding) \
-  (coding)->spec.iso2022.bol
-
-/* A value which may appear in
-   coding->spec.iso2022.requested_designation indicating that the
-   corresponding charset does not request any graphic register to be
-   designated.  */
-#define CODING_SPEC_ISO_NO_REQUESTED_DESIGNATION 4
-
-/* Return a charset which is currently designated to the graphic plane
-   PLANE in the coding-system CODING.  */
-#define CODING_SPEC_ISO_PLANE_CHARSET(coding, plane)    \
-  ((CODING_SPEC_ISO_INVOCATION (coding, plane) < 0)     \
-   ? -1                                                 \
-   : CODING_SPEC_ISO_DESIGNATION (coding,               \
-                                  CODING_SPEC_ISO_INVOCATION (coding, plane)))
-
-/*** BIG5 section ***/
-
-/* Macros to denote each type of BIG5 coding system.  */
-#define CODING_FLAG_BIG5_HKU    0x00 /* BIG5-HKU is one of variants of
-                                        BIG5 developed by Hong Kong
-                                        University.  */
-#define CODING_FLAG_BIG5_ETEN   0x01 /* BIG5_ETen is one of variants
-                                        of BIG5 developed by the
-                                        company ETen in Taiwan.  */
 
 /*** GENERAL section ***/
 
-/* Types of coding system.  */
-enum coding_type
+/* Enumeration of result code of code conversion.  */
+enum coding_result_code
   {
-    coding_type_no_conversion,  /* A coding system which requires no
-                                   conversion for reading and writing
-                                   including end-of-line format.  */
-    coding_type_emacs_mule,     /* A coding system used in Emacs'
-                                   buffer and string.  Requires no
-                                   conversion for reading and writing
-                                   except for end-of-line format.  */
-    coding_type_undecided,      /* A coding system which requires
-                                   automatic detection of a real
-                                   coding system.  */
-    coding_type_sjis,           /* SJIS coding system for Japanese.  */
-    coding_type_iso2022,        /* Any coding system of ISO2022
-                                   variants.  */
-    coding_type_big5,           /* BIG5 coding system for Chinese.  */
-    coding_type_ccl,            /* The coding system of which decoder
-                                   and encoder are written in CCL.  */
-    coding_type_raw_text        /* A coding system for a text
-                                   containing random 8-bit code which
-                                   does not require code conversion
-                                   except for end-of-line format. */
+    CODING_RESULT_SUCCESS,
+    CODING_RESULT_INSUFFICIENT_SRC,
+    CODING_RESULT_INSUFFICIENT_DST,
+    CODING_RESULT_INCONSISTENT_EOL,
+    CODING_RESULT_INSUFFICIENT_CMP,
+    CODING_RESULT_INTERRUPT,
+    CODING_RESULT_INSUFFICIENT_MEM
   };
 
-/* Formats of end-of-line.  */
-#define CODING_EOL_LF   0       /* Line-feed only, same as Emacs'
-                                   internal format.  */
-#define CODING_EOL_CRLF 1       /* Sequence of carriage-return and
-                                   line-feed.  */
-#define CODING_EOL_CR   2       /* Carriage-return only.  */
-#define CODING_EOL_UNDECIDED 3  /* This value is used to denote the
-                                   eol-type is not yet decided.  */
-#define CODING_EOL_INCONSISTENT 4 /* This value is used to denote the
-                                     eol-type is not consistent
-                                     through the file.  */
-
-/* 1 iff composing.  */
-#define COMPOSING_P(coding) ((int) coding->composing > (int) COMPOSITION_NO)
-
-#define COMPOSITION_DATA_SIZE 4080
-#define COMPOSITION_DATA_MAX_BUNCH_LENGTH (4 + MAX_COMPOSITION_COMPONENTS*2)
-
-/* Data structure to hold information about compositions of text that
-   is being decoded or encode.  ISO 2022 base code conversion routines
-   handle special ESC sequences for composition specification.  But,
-   they can't get/put such information directly from/to a buffer in
-   the deepest place.  So, they store or retrieve the information
-   through this structure.
-
-   The encoder stores the information in this structure when it meets
-   ESC sequences for composition while encoding codes, then, after all
-   text codes are encoded, puts `composition' properties on the text
-   by referring to the structure.
-
-   The decoder at first stores the information of a text to be
-   decoded, then, while decoding codes, generates ESC sequences for
-   composition at proper places by referring to the structure.  */
-
-struct composition_data
-{
-  /* The character position of the first character to be encoded or
-     decoded.  START and END (see below) are relative to this
-     position.  */
-  int char_offset;
-
-  /* The composition data.  These elements are repeated for each
-     composition:
-        LENGTH START END METHOD [ COMPONENT ... ]
-     where,
-        LENGTH is the number of elements for this composition.
-
-        START and END are starting and ending character positions of
-        the composition relative to `char_offset'.
-
-        METHOD is one of `enum composing_status' specifying the way of
-        composition.
-
-        COMPONENT is a character or an encoded composition rule.  */
-  int data[COMPOSITION_DATA_SIZE];
-
-  /* The number of elements in `data' currently used.  */
-  int used;
-
-  /* Pointers to the previous and next structures.  When `data' is
-     filled up, another structure is allocated and linked in `next'.
-     The new structure has backward link to this structure in `prev'.
-     The number of chained structures depends on how many compositions
-     the text being encoded or decoded contains.  */
-  struct composition_data *prev, *next;
-};
-
-/* Macros used for the member `result' of the struct
-   coding_system.  */
-#define CODING_FINISH_NORMAL            0
-#define CODING_FINISH_INSUFFICIENT_SRC  1
-#define CODING_FINISH_INSUFFICIENT_DST  2
-#define CODING_FINISH_INCONSISTENT_EOL  3
-#define CODING_FINISH_INSUFFICIENT_CMP  4
-#define CODING_FINISH_INTERRUPT         5
 
 /* Macros used for the member `mode' of the struct coding_system.  */
 
@@ -330,7 +231,7 @@ struct composition_data
 
 /* If set, the decoding/encoding routines treat the current data as
    the last block of the whole text to be converted, and do
-   appropriate finishing job.  */
+   appropriate fisishing job.  */
 #define CODING_MODE_LAST_BLOCK                  0x02
 
 /* If set, it means that the current source text is in a buffer which
@@ -341,58 +242,88 @@ struct composition_data
    set, it means that right-to-left text is being processed.  */
 #define CODING_MODE_DIRECTION                   0x08
 
-struct coding_system
+#define CODING_MODE_FIXED_DESTINATION           0x10
+
+#define CODING_MODE_SAFE_ENCODING               0x20
+
+/* Structure of the field `spec.iso_2022' in the structure
+   `coding_system'.  */
+struct iso_2022_spec
 {
-  /* Type of the coding system.  */
-  enum coding_type type;
+  /*  */
+  unsigned flags;
 
-  /* Type of end-of-line format (LF, CRLF, or CR) of the coding system.  */
-  int eol_type;
+  /* The current graphic register invoked to each graphic plane.  */
+  int current_invocation[2];
 
-  /* Flag bits of the coding system.  The meaning of each bit is common
-     to all types of coding systems.  */
-  unsigned int common_flags;
+  /* The current charset designated to each graphic register.  The
+     value -1 means that not charset is designated, -2 means that
+     there was an invalid designation previously.  */
+  int current_designation[4];
 
-  /* Flag bits of the coding system.  The meaning of each bit depends
-     on the type of the coding system.  */
-  unsigned int flags;
+  /* Set to 1 temporarily only when graphic register 2 or 3 is invoked
+     by single-shift while encoding.  */
+  int single_shifting;
 
-  /* Mode bits of the coding system.  See the comments of the macros
-     CODING_MODE_XXX.  */
-  unsigned int mode;
+  /* Set to 1 temporarily only when processing at beginning of line.  */
+  int bol;
+};
 
-  /* The current status of composition handling.  */
-  int composing;
+struct ccl_spec;
 
-  /* 1 iff the next character is a composition rule.  */
-  int composition_rule_follows;
+enum utf_16_bom_type
+  {
+    utf_16_detect_bom,
+    utf_16_without_bom,
+    utf_16_with_bom
+  };
 
-  /* Information of compositions are stored here on decoding and set
-     in advance on encoding.  */
-  struct composition_data *cmp_data;
+enum utf_16_endian_type
+  {
+    utf_16_big_endian,
+    utf_16_little_endian
+  };
 
-  /* Index to cmp_data->data for the first element for the current
-     composition.  */
-  int cmp_data_start;
+struct utf_16_spec
+{
+  enum utf_16_bom_type bom;
+  enum utf_16_endian_type endian;
+  int surrogate;
+};
 
-  /* Index to cmp_data->data for the current element for the current
-     composition.  */
-  int cmp_data_index;
+struct coding_system
+{
+  /* ID number of the coding system.  This is an index to
+     Vcoding_system_hash_table.  This value is set by
+     setup_coding_system.  At the early stage of building time, this
+     value is -1 in the array coding_categories to indicate that no
+     coding-system of that category is yet defined.  */
+  int id;
+
+  /* Flag bits of the coding system.  The meaning of each bit is common
+     to all types of coding systems.  */
+  int common_flags;
+
+  /* Mode bits of the coding system.  See the comments of the macros
+     CODING_MODE_XXX.  */
+  unsigned int mode;
 
   /* Detailed information specific to each type of coding system.  */
-  union spec
+  union
     {
-      struct iso2022_spec iso2022;
-      struct ccl_spec ccl;      /* Defined in ccl.h.  */
+      struct iso_2022_spec iso_2022;
+      struct ccl_spec *ccl;     /* Defined in ccl.h.  */
+      struct utf_16_spec utf_16;
+      int emacs_mule_full_support;
     } spec;
 
-  /* Index number of coding category of the coding system.  */
-  int category_idx;
+  int max_charset_id;
+  char *safe_charsets;
 
-  /* The following two members specify how characters 128..159 are
-     represented in source and destination text respectively.  1 means
-     they are represented by 2-byte sequence, 0 means they are
-     represented by 1-byte as is (see the comment in charset.h).  */
+  /* The following two members specify how binary 8-bit code 128..255
+     are represented in source and destination text respectively.  1
+     means they are represented by 2-byte sequence, 0 means they are
+     represented by 1-byte as is (see the comment in character.h).  */
   unsigned src_multibyte : 1;
   unsigned dst_multibyte : 1;
 
@@ -400,170 +331,152 @@ struct coding_system
      -1 in setup_coding_system, and updated by detect_coding.  So,
      when this is equal to the byte length of the text being
      converted, we can skip the actual conversion process.  */
-  int heading_ascii;
+  int head_ascii;
 
   /* The following members are set by encoding/decoding routine.  */
-  int produced, produced_char, consumed, consumed_char;
+  EMACS_INT produced, produced_char, consumed, consumed_char;
 
   /* Number of error source data found in a decoding routine.  */
   int errors;
 
-  /* Finish status of code conversion.  It should be one of macros
-     CODING_FINISH_XXXX.  */
-  int result;
+  /* Store the positions of error source data. */
+  EMACS_INT *error_positions;
 
-  /* If nonzero, suppress error notification.  */
-  int suppress_error;
+  /* Finish status of code conversion.  */
+  enum coding_result_code result;
 
   /* The following members are all Lisp symbols.  We don't have to
      protect them from GC because the current garbage collection
      doesn't relocate Lisp symbols.  But, when it is changed, we must
      find a way to protect them.  */
 
-  /* Backward pointer to the Lisp symbol of the coding system.  */
-  Lisp_Object symbol;
+  EMACS_INT src_pos, src_pos_byte, src_chars, src_bytes;
+  Lisp_Object src_object;
+  unsigned char *source;
 
-  /* Lisp function (symbol) to be called after decoding to do
-     additional conversion, or nil.  */
-  Lisp_Object post_read_conversion;
+  EMACS_INT dst_pos, dst_pos_byte, dst_bytes;
+  Lisp_Object dst_object;
+  unsigned char *destination;
 
-  /* Lisp function (symbol) to be called before encoding to do
-     additional conversion, or nil.  */
-  Lisp_Object pre_write_conversion;
+  int chars_at_source;
 
-  /* Character translation tables to look up, or nil.  */
-  Lisp_Object translation_table_for_decode;
-  Lisp_Object translation_table_for_encode;
-};
+  /* If an element is non-negative, it is a character code.
+
+     If it is in the range -128..-1, it is a 8-bit character code
+     minus 256.
+
+     If it is less than -128, it specifies the start of an annotation
+     chunk.  The length of the chunk is -128 minus the value of the
+     element.  The following elements are OFFSET, ANNOTATION-TYPE, and
+     a sequence of actual data for the annotation.  OFFSET is a
+     character position offset from dst_pos or src_pos,
+     ANNOTATION-TYPE specfies the meaning of the annotation and how to
+     handle the following data..  */
+  int *charbuf;
+  int charbuf_size, charbuf_used;
+
+  /* Set to 1 if charbuf contains an annotation.  */
+  int annotated;
 
-#define CODING_REQUIRE_FLUSHING_MASK    1
-#define CODING_REQUIRE_DECODING_MASK    2
-#define CODING_REQUIRE_ENCODING_MASK    4
-#define CODING_REQUIRE_DETECTION_MASK   8
+  unsigned char carryover[64];
+  int carryover_bytes;
 
-/* Return 1 if the coding system CODING requires specific code to be
+  int default_char;
+
+  int (*detector) P_ ((struct coding_system *, int *));
+  void (*decoder) P_ ((struct coding_system *));
+  int (*encoder) P_ ((struct coding_system *));
+};
+
+/* Meanings of bits in the member `common_flags' of the structure
+   coding_system.  The lowest 8 bits are reserved for various kind of
+   annotations (currently two of them are used).  */
+#define CODING_ANNOTATION_MASK                  0x00FF
+#define CODING_ANNOTATE_COMPOSITION_MASK        0x0001
+#define CODING_ANNOTATE_DIRECTION_MASK          0x0002
+#define CODING_FOR_UNIBYTE_MASK                 0x0100
+#define CODING_REQUIRE_FLUSHING_MASK            0x0200
+#define CODING_REQUIRE_DECODING_MASK            0x0400
+#define CODING_REQUIRE_ENCODING_MASK            0x0800
+#define CODING_REQUIRE_DETECTION_MASK           0x1000
+#define CODING_RESET_AT_BOL_MASK                0x2000
+
+/* Return 1 if the coding context CODING requires annotaion
+   handling.  */
+#define CODING_REQUIRE_ANNOTATION(coding) \
+  ((coding)->common_flags & CODING_ANNOTATION_MASK)
+
+/* Return 1 if the coding context CODING prefers decoding into unibyte.  */
+#define CODING_FOR_UNIBYTE(coding) \
+  ((coding)->common_flags & CODING_FOR_UNIBYTE_MASK)
+
+/* Return 1 if the coding context CODING requires specific code to be
    attached at the tail of converted text.  */
 #define CODING_REQUIRE_FLUSHING(coding) \
   ((coding)->common_flags & CODING_REQUIRE_FLUSHING_MASK)
 
-/* Return 1 if the coding system CODING requires code conversion on
+/* Return 1 if the coding context CODING requires code conversion on
    decoding.  */
 #define CODING_REQUIRE_DECODING(coding) \
   ((coding)->dst_multibyte              \
    || (coding)->common_flags & CODING_REQUIRE_DECODING_MASK)
 
-/* Return 1 if the coding system CODING requires code conversion on
+
+/* Return 1 if the coding context CODING requires code conversion on
    encoding.  */
-#define CODING_REQUIRE_ENCODING(coding) \
-  ((coding)->src_multibyte              \
-   || (coding)->common_flags & CODING_REQUIRE_ENCODING_MASK)
+#define CODING_REQUIRE_ENCODING(coding)                         \
+  ((coding)->src_multibyte                                      \
+   || (coding)->common_flags & CODING_REQUIRE_ENCODING_MASK     \
+   || (coding)->mode & CODING_MODE_SELECTIVE_DISPLAY)
+
 
-/* Return 1 if the coding system CODING requires some kind of code
+/* Return 1 if the coding context CODING requires some kind of code
    detection.  */
 #define CODING_REQUIRE_DETECTION(coding) \
   ((coding)->common_flags & CODING_REQUIRE_DETECTION_MASK)
 
-/* Return 1 if the coding system CODING requires code conversion on
+/* Return 1 if the coding context CODING requires code conversion on
    decoding or some kind of code detection.  */
 #define CODING_MAY_REQUIRE_DECODING(coding)     \
   (CODING_REQUIRE_DECODING (coding)             \
    || CODING_REQUIRE_DETECTION (coding))
 
-/* Index for each coding category in `coding_category_table' */
-#define CODING_CATEGORY_IDX_EMACS_MULE  0
-#define CODING_CATEGORY_IDX_SJIS        1
-#define CODING_CATEGORY_IDX_ISO_7       2
-#define CODING_CATEGORY_IDX_ISO_7_TIGHT 3
-#define CODING_CATEGORY_IDX_ISO_8_1     4
-#define CODING_CATEGORY_IDX_ISO_8_2     5
-#define CODING_CATEGORY_IDX_ISO_7_ELSE  6
-#define CODING_CATEGORY_IDX_ISO_8_ELSE  7
-#define CODING_CATEGORY_IDX_CCL         8
-#define CODING_CATEGORY_IDX_BIG5        9
-#define CODING_CATEGORY_IDX_UTF_8       10
-#define CODING_CATEGORY_IDX_UTF_16_BE   11
-#define CODING_CATEGORY_IDX_UTF_16_LE   12
-#define CODING_CATEGORY_IDX_RAW_TEXT    13
-#define CODING_CATEGORY_IDX_BINARY      14
-#define CODING_CATEGORY_IDX_MAX         15
-
-/* Definitions of flag bits returned by the function
-   detect_coding_mask ().  */
-#define CODING_CATEGORY_MASK_EMACS_MULE (1 << CODING_CATEGORY_IDX_EMACS_MULE)
-#define CODING_CATEGORY_MASK_SJIS       (1 << CODING_CATEGORY_IDX_SJIS)
-#define CODING_CATEGORY_MASK_ISO_7      (1 << CODING_CATEGORY_IDX_ISO_7)
-#define CODING_CATEGORY_MASK_ISO_7_TIGHT (1 << CODING_CATEGORY_IDX_ISO_7_TIGHT)
-#define CODING_CATEGORY_MASK_ISO_8_1    (1 << CODING_CATEGORY_IDX_ISO_8_1)
-#define CODING_CATEGORY_MASK_ISO_8_2    (1 << CODING_CATEGORY_IDX_ISO_8_2)
-#define CODING_CATEGORY_MASK_ISO_7_ELSE (1 << CODING_CATEGORY_IDX_ISO_7_ELSE)
-#define CODING_CATEGORY_MASK_ISO_8_ELSE (1 << CODING_CATEGORY_IDX_ISO_8_ELSE)
-#define CODING_CATEGORY_MASK_CCL        (1 << CODING_CATEGORY_IDX_CCL)
-#define CODING_CATEGORY_MASK_BIG5       (1 << CODING_CATEGORY_IDX_BIG5)
-#define CODING_CATEGORY_MASK_UTF_8      (1 << CODING_CATEGORY_IDX_UTF_8)
-#define CODING_CATEGORY_MASK_UTF_16_BE  (1 << CODING_CATEGORY_IDX_UTF_16_BE)
-#define CODING_CATEGORY_MASK_UTF_16_LE  (1 << CODING_CATEGORY_IDX_UTF_16_LE)
-#define CODING_CATEGORY_MASK_RAW_TEXT   (1 << CODING_CATEGORY_IDX_RAW_TEXT)
-#define CODING_CATEGORY_MASK_BINARY     (1 << CODING_CATEGORY_IDX_BINARY)
-
-/* This value is returned if detect_coding_mask () find nothing other
-   than ASCII characters.  */
-#define CODING_CATEGORY_MASK_ANY        \
-  (  CODING_CATEGORY_MASK_EMACS_MULE    \
-   | CODING_CATEGORY_MASK_SJIS          \
-   | CODING_CATEGORY_MASK_ISO_7         \
-   | CODING_CATEGORY_MASK_ISO_7_TIGHT   \
-   | CODING_CATEGORY_MASK_ISO_8_1       \
-   | CODING_CATEGORY_MASK_ISO_8_2       \
-   | CODING_CATEGORY_MASK_ISO_7_ELSE    \
-   | CODING_CATEGORY_MASK_ISO_8_ELSE    \
-   | CODING_CATEGORY_MASK_CCL           \
-   | CODING_CATEGORY_MASK_BIG5          \
-   | CODING_CATEGORY_MASK_UTF_8         \
-   | CODING_CATEGORY_MASK_UTF_16_BE     \
-   | CODING_CATEGORY_MASK_UTF_16_LE)
-
-#define CODING_CATEGORY_MASK_ISO_7BIT \
-  (CODING_CATEGORY_MASK_ISO_7 | CODING_CATEGORY_MASK_ISO_7_TIGHT)
-
-#define CODING_CATEGORY_MASK_ISO_8BIT \
-  (CODING_CATEGORY_MASK_ISO_8_1 | CODING_CATEGORY_MASK_ISO_8_2)
-
-#define CODING_CATEGORY_MASK_ISO_SHIFT \
-  (CODING_CATEGORY_MASK_ISO_7_ELSE | CODING_CATEGORY_MASK_ISO_8_ELSE)
-
-#define CODING_CATEGORY_MASK_ISO        \
-  (  CODING_CATEGORY_MASK_ISO_7BIT      \
-   | CODING_CATEGORY_MASK_ISO_SHIFT     \
-   | CODING_CATEGORY_MASK_ISO_8BIT)
-
-#define CODING_CATEGORY_MASK_UTF_16_BE_LE \
-   (CODING_CATEGORY_MASK_UTF_16_BE | CODING_CATEGORY_MASK_UTF_16_LE)
-
 /* Macros to decode or encode a character of JISX0208 in SJIS.  S1 and
    S2 are the 1st and 2nd position-codes of JISX0208 in SJIS coding
    system.  C1 and C2 are the 1st and 2nd position codes of Emacs'
    internal format.  */
 
-#define DECODE_SJIS(s1, s2, c1, c2)                     \
-  do {                                                  \
-    if (s2 >= 0x9F)                                     \
-      c1 = s1 * 2 - (s1 >= 0xE0 ? 0x160 : 0xE0),        \
-      c2 = s2 - 0x7E;                                   \
-    else                                                \
-      c1 = s1 * 2 - ((s1 >= 0xE0) ? 0x161 : 0xE1),      \
-      c2 = s2 - ((s2 >= 0x7F) ? 0x20 : 0x1F);           \
+#define SJIS_TO_JIS(code)                               \
+  do {                                                  \
+    int s1, s2, j1, j2;                                 \
+                                                        \
+    s1 = (code) >> 8, s2 = (code) & 0xFF;               \
+                                                        \
+    if (s2 >= 0x9F)                                     \
+      (j1 = s1 * 2 - (s1 >= 0xE0 ? 0x160 : 0xE0),       \
+       j2 = s2 - 0x7E);                                 \
+    else                                                \
+      (j1 = s1 * 2 - ((s1 >= 0xE0) ? 0x161 : 0xE1),     \
+       j2 = s2 - ((s2 >= 0x7F) ? 0x20 : 0x1F));         \
+    (code) = (j1 << 8) | j2;                            \
   } while (0)
 
-#define ENCODE_SJIS(c1, c2, s1, s2)                     \
+
+#define JIS_TO_SJIS(code)                               \
   do {                                                  \
-    if (c1 & 1)                                         \
-      s1 = c1 / 2 + ((c1 < 0x5F) ? 0x71 : 0xB1),        \
-      s2 = c2 + ((c2 >= 0x60) ? 0x20 : 0x1F);           \
+    int s1, s2, j1, j2;                                 \
+                                                        \
+    j1 = (code) >> 8, j2 = (code) & 0xFF;               \
+    if (j1 & 1)                                         \
+      (s1 = j1 / 2 + ((j1 < 0x5F) ? 0x71 : 0xB1),       \
+       s2 = j2 + ((j2 >= 0x60) ? 0x20 : 0x1F));         \
     else                                                \
-      s1 = c1 / 2 + ((c1 < 0x5F) ? 0x70 : 0xB0),        \
-      s2 = c2 + 0x7E;                                   \
+      (s1 = j1 / 2 + ((j1 < 0x5F) ? 0x70 : 0xB0),       \
+       s2 = j2 + 0x7E);                                 \
+    (code) = (j1 << 8) | j2;                            \
   } while (0)
 
+
 /* Encode the file name NAME using the specified coding system
    for file names, if any.  */
 #define ENCODE_FILE(name)                                                  \
@@ -575,6 +488,7 @@ struct coding_system
       ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 1) \
       : name))
 
+
 /* Decode the file name NAME using the specified coding system
    for file names, if any.  */
 #define DECODE_FILE(name)                                                  \
@@ -586,21 +500,22 @@ struct coding_system
       ? code_convert_string_norecord (name, Vdefault_file_name_coding_system, 0) \
       : name))
 
+
 #ifdef WINDOWSNT
 /* Encode the string STR using the specified coding system
    for w32 system functions, if any.  */
-#define ENCODE_SYSTEM(str)                                                 \
-  (! NILP (Vlocale_coding_system)                                          \
-   && XFASTINT (Vlocale_coding_system) != 0                                \
-   ? code_convert_string_norecord (str, Vlocale_coding_system, 1)          \
+#define ENCODE_SYSTEM(str)                                              \
+  (! NILP (Vlocale_coding_system)                                       \
+   && XFASTINT (Vlocale_coding_system) != 0                             \
+   ? code_convert_string_norecord (str, Vlocale_coding_system, 1)       \
    : str)
 
 /* Decode the string STR using the specified coding system
    for w32 system functions, if any.  */
-#define DECODE_SYSTEM(name)                                                \
-  (! NILP (Vlocale_coding_system)                                          \
-   && XFASTINT (Vlocale_coding_system) != 0                                \
-   ? code_convert_string_norecord (str, Vlocale_coding_system, 0)          \
+#define DECODE_SYSTEM(name)                                             \
+  (! NILP (Vlocale_coding_system)                                       \
+   && XFASTINT (Vlocale_coding_system) != 0                             \
+   ? code_convert_string_norecord (str, Vlocale_coding_system, 0)       \
    : str)
 
 #else /* WINDOWSNT */
@@ -611,44 +526,74 @@ struct coding_system
 #endif /* !WINDOWSNT */
 
 /* Extern declarations.  */
-extern int decode_coding P_ ((struct coding_system *, unsigned char *,
-                              unsigned char *, int, int));
-extern int encode_coding P_ ((struct coding_system *, unsigned char *,
-                              unsigned char *, int, int));
-extern void coding_save_composition P_ ((struct coding_system *, int, int,
-                                         Lisp_Object));
-extern void coding_free_composition_data P_ ((struct coding_system *));
-extern void coding_adjust_composition_offset P_ ((struct coding_system *,
-                                                  int));
-extern void coding_allocate_composition_data P_ ((struct coding_system *,
-                                                  int));
-extern void coding_restore_composition P_ ((struct coding_system *,
-                                            Lisp_Object));
-extern int code_convert_region P_ ((int, int, int, int, struct coding_system *,
-                                    int, int));
-extern Lisp_Object run_pre_post_conversion_on_str P_ ((Lisp_Object,
-                                                       struct coding_system *,
-                                                       int));
+extern Lisp_Object make_conversion_work_buffer P_ ((int));
+extern Lisp_Object code_conversion_restore P_ ((Lisp_Object));
 extern int decoding_buffer_size P_ ((struct coding_system *, int));
 extern int encoding_buffer_size P_ ((struct coding_system *, int));
-extern void detect_coding P_ ((struct coding_system *, unsigned char *, int));
-extern void detect_eol P_ ((struct coding_system *, unsigned char *, int));
-extern int setup_coding_system P_ ((Lisp_Object, struct coding_system *));
-extern Lisp_Object code_convert_string P_ ((Lisp_Object,
-                                            struct coding_system *, int, int));
-extern Lisp_Object code_convert_string1 P_ ((Lisp_Object, Lisp_Object,
-                                             Lisp_Object, int));
+extern void setup_coding_system P_ ((Lisp_Object, struct coding_system *));
+extern void detect_coding P_ ((struct coding_system *));
+extern Lisp_Object code_convert_region P_ ((EMACS_INT, EMACS_INT,
+                                            Lisp_Object, Lisp_Object,
+                                            int, int));
+extern Lisp_Object code_convert_string P_ ((Lisp_Object, Lisp_Object,
+                                            Lisp_Object, int, int, int));
 extern Lisp_Object code_convert_string_norecord P_ ((Lisp_Object, Lisp_Object,
                                                      int));
-extern void setup_raw_text_coding_system P_ ((struct coding_system *));
-extern Lisp_Object encode_coding_string P_ ((Lisp_Object,
-                                             struct coding_system *, int));
-extern Lisp_Object decode_coding_string P_ ((Lisp_Object,
-                                             struct coding_system *, int));
+extern Lisp_Object raw_text_coding_system P_ ((Lisp_Object));
+extern Lisp_Object coding_inherit_eol_type P_ ((Lisp_Object, Lisp_Object));
+
+extern int decode_coding_gap P_ ((struct coding_system *,
+                                  EMACS_INT, EMACS_INT));
+extern int encode_coding_gap P_ ((struct coding_system *,
+                                  EMACS_INT, EMACS_INT));
+extern void decode_coding_object P_ ((struct coding_system *,
+                                      Lisp_Object, EMACS_INT, EMACS_INT,
+                                      EMACS_INT, EMACS_INT, Lisp_Object));
+extern void encode_coding_object P_ ((struct coding_system *,
+                                      Lisp_Object, EMACS_INT, EMACS_INT,
+                                      EMACS_INT, EMACS_INT, Lisp_Object));
+
+#define decode_coding_region(coding, from, to)          \
+  decode_coding_object (coding, Fcurrent_buffer (),     \
+                        from, CHAR_TO_BYTE (from),      \
+                        to, CHAR_TO_BYTE (to), Fcurrent_buffer ())
+
+
+#define encode_coding_region(coding, from, to)          \
+  encode_coding_object (coding, Fcurrent_buffer (),     \
+                        from, CHAR_TO_BYTE (from),      \
+                        to, CHAR_TO_BYTE (to), Fcurrent_buffer ())
+
+
+#define decode_coding_string(coding, string, nocopy)                    \
+  decode_coding_object (coding, string, 0, 0, XSTRING (string)->size,   \
+                        STRING_BYTES (XSTRING (string)), Qt)
+
+#define encode_coding_string(coding, string, nocopy)                    \
+  (encode_coding_object (coding, string, 0, 0, XSTRING (string)->size,  \
+                         STRING_BYTES (XSTRING (string)), Qt),          \
+   (coding)->dst_object)
+
+
+#define decode_coding_c_string(coding, src, bytes, dst_object)          \
+  do {                                                                  \
+    (coding)->source = (src);                                           \
+    (coding)->src_chars = (coding)->src_bytes = (bytes);                \
+    decode_coding_object ((coding), Qnil, 0, 0, (bytes), (bytes),       \
+                          (dst_object));                                \
+  } while (0)
+
+
+extern Lisp_Object preferred_coding_system P_ (());
+
+
 extern Lisp_Object Qcoding_system, Qeol_type, Qcoding_category_index;
-extern Lisp_Object Qraw_text, Qemacs_mule;
+extern Lisp_Object Qcoding_system_p;
+extern Lisp_Object Qraw_text, Qemacs_mule, Qno_conversion, Qundecided;
+extern Lisp_Object Qiso_2022;
 extern Lisp_Object Qbuffer_file_coding_system;
-extern Lisp_Object Vcoding_category_list;
+
+extern Lisp_Object Qunix, Qdos, Qmac;
 
 extern Lisp_Object Qtranslation_table;
 extern Lisp_Object Qtranslation_table_id;
@@ -693,13 +638,10 @@ extern struct coding_system safe_terminal_coding;
    function `set-keyboard-coding-system'.  */
 extern struct coding_system keyboard_coding;
 
-/* Default coding system to be used to write a file.  */
-extern struct coding_system default_buffer_file_coding;
-
 /* Default coding systems used for process I/O.  */
 extern Lisp_Object Vdefault_process_coding_system;
 
-/* Function to call to force a user to force select a proper coding
+/* Function to call to force a user to force select a propert coding
    system.  */
 extern Lisp_Object Vselect_safe_coding_system_function;
 
@@ -715,4 +657,7 @@ extern Lisp_Object Vdefault_file_name_coding_system;
 /* Error signaled when there's a problem with detecting coding system */
 extern Lisp_Object Qcoding_system_error;
 
+extern char emacs_mule_bytes[256];
+extern int emacs_mule_string_char P_ ((unsigned char *));
+
 #endif /* EMACS_CODING_H */