iconvdata/ibm935.c

   1 /* Conversion from and to IBM935
   2    Copyright (C) 2000-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* IBM935 is designed for the representation of Simplified Chinese
  20    using a stateful EBCDIC encoding scheme.  It is also known as
  21    CCSID 935 or CP935. See:
  22    https://www-01.ibm.com/software/globalization/ccsid/ccsid935.html  */
  23
  24 #include <dlfcn.h>
  25 #include <stdint.h>
  26 #include <wchar.h>
  27 #include <byteswap.h>
  28 #include "ibm935.h"
  29
  30 /* The shift sequences for this charset (it does not use ESC).  */
  31 #define SI              0x0F  /* Shift In, host code to turn DBCS off.  */
  32 #define SO              0x0E  /* Shift Out, host code to turn DBCS on.  */
  33
  34 /* Definitions used in the body of the `gconv' function.  */
  35 #define CHARSET_NAME    "IBM935//"
  36 #define FROM_LOOP       from_ibm935
  37 #define TO_LOOP         to_ibm935
  38 #define ONE_DIRECTION                   0
  39 #define FROM_LOOP_MIN_NEEDED_FROM       1
  40 #define FROM_LOOP_MAX_NEEDED_FROM       2
  41 #define FROM_LOOP_MIN_NEEDED_TO         4
  42 #define FROM_LOOP_MAX_NEEDED_TO         4
  43 #define TO_LOOP_MIN_NEEDED_FROM         4
  44 #define TO_LOOP_MAX_NEEDED_FROM         4
  45 #define TO_LOOP_MIN_NEEDED_TO           1
  46 #define TO_LOOP_MAX_NEEDED_TO           3
  47 #define PREPARE_LOOP \
  48   int save_curcs;                                                             \
  49   int *curcsp = &data->__statep->__count;
  50 #define EXTRA_LOOP_ARGS         , curcsp
  51
  52 /* Definitions of initialization and destructor function.  */
  53 #define DEFINE_INIT     1
  54 #define DEFINE_FINI     1
  55
  56
  57 /* Since this is a stateful encoding we have to provide code which resets
  58    the output state to the initial state.  This has to be done during the
  59    flushing.  */
  60 #define EMIT_SHIFT_TO_INIT \
  61   if ((data->__statep->__count & ~7) != sb)                                   \
  62     {                                                                         \
  63       if (FROM_DIRECTION)                                                     \
  64         data->__statep->__count &= 7;                                         \
  65       else                                                                    \
  66         {                                                                     \
  67           /* We are not in the initial state.  To switch back we have         \
  68              to emit `SI'.  */                                                \
  69           if (__glibc_unlikely (outbuf >= outend))                            \
  70             /* We don't have enough room in the output buffer.  */            \
  71             status = __GCONV_FULL_OUTPUT;                                     \
  72           else                                                                \
  73             {                                                                 \
  74               /* Write out the shift sequence.  */                            \
  75               *outbuf++ = SI;                                                 \
  76               data->__statep->__count &= 7;                                   \
  77             }                                                                 \
  78         }                                                                     \
  79     }
  80
  81
  82 /* Since we might have to reset input pointer we must be able to save
  83    and retore the state.  */
  84 #define SAVE_RESET_STATE(Save) \
  85   if (Save)                                                                   \
  86     save_curcs = *curcsp;                                                     \
  87   else                                                                        \
  88     *curcsp = save_curcs
  89
  90
  91 /* Current codeset type.  */
  92 enum
  93 {
  94   sb = 0,
  95   db = 64
  96 };
  97
  98 /* First, define the conversion function from IBM-935 to UCS4.  */
  99 #define MIN_NEEDED_INPUT        FROM_LOOP_MIN_NEEDED_FROM
 100 #define MAX_NEEDED_INPUT        FROM_LOOP_MAX_NEEDED_FROM
 101 #define MIN_NEEDED_OUTPUT       FROM_LOOP_MIN_NEEDED_TO
 102 #define MAX_NEEDED_OUTPUT       FROM_LOOP_MAX_NEEDED_TO
 103 #define LOOPFCT                 FROM_LOOP
 104 #define BODY \
 105   {                                                                           \
 106     uint32_t ch = *inptr;                                                     \
 107     uint32_t res;                                                             \
 108                                                                               \
 109     if (__builtin_expect(ch, 0) == SO)                                        \
 110       {                                                                       \
 111         /* Shift OUT, change to DBCS converter (redundant escape okay).  */   \
 112         curcs = db;                                                           \
 113         ++inptr;                                                              \
 114         continue;                                                             \
 115       }                                                                       \
 116     else if (__builtin_expect (ch, 0) == SI)                                  \
 117       {                                                                       \
 118         /* Shift IN, change to SBCS converter (redundant escape okay).  */    \
 119         curcs = sb;                                                           \
 120         ++inptr;                                                              \
 121         continue;                                                             \
 122       }                                                                       \
 123                                                                               \
 124     if (curcs == sb)                                                          \
 125       {                                                                       \
 126         /* Use the IBM935 table for single byte.  */                          \
 127         res = __ibm935sb_to_ucs4[ch];                                         \
 128         if (__builtin_expect (res, L'\1') == L'\0' && ch != '\0')             \
 129           {                                                                   \
 130             /* This is an illegal character.  */                              \
 131             STANDARD_FROM_LOOP_ERR_HANDLER (1);                               \
 132           }                                                                   \
 133         else                                                                  \
 134           {                                                                   \
 135             put32 (outptr, res);                                              \
 136             outptr += 4;                                                      \
 137           }                                                                   \
 138         ++inptr;                                                              \
 139       }                                                                       \
 140     else                                                                      \
 141       {                                                                       \
 142         const struct gap *rp2 = __ibm935db_to_ucs4_idx;                       \
 143                                                                               \
 144         assert (curcs == db);                                                 \
 145                                                                               \
 146         /* Use the IBM935 table for double byte.  */                          \
 147         if (__glibc_unlikely (inptr + 1 >= inend))                            \
 148           {                                                                   \
 149             /* The second character is not available.                         \
 150                Store the intermediate result. */                              \
 151             result = __GCONV_INCOMPLETE_INPUT;                                \
 152             break;                                                            \
 153           }                                                                   \
 154                                                                               \
 155         ch = (ch * 0x100) + inptr[1];                                         \
 156         while (ch > rp2->end)                                                 \
 157           ++rp2;                                                              \
 158                                                                               \
 159         if (__builtin_expect (rp2->start == 0xffff, 0)                        \
 160             || __builtin_expect (ch < rp2->start, 0)                          \
 161             || (res = __ibm935db_to_ucs4[ch + rp2->idx],                      \
 162                 __builtin_expect (res, L'\1') == L'\0' && ch != '\0'))        \
 163           {                                                                   \
 164             /* This is an illegal character.  */                              \
 165             STANDARD_FROM_LOOP_ERR_HANDLER (2);                               \
 166           }                                                                   \
 167         else                                                                  \
 168           {                                                                   \
 169             put32 (outptr, res);                                              \
 170             outptr += 4;                                                      \
 171           }                                                                   \
 172         inptr += 2;                                                           \
 173       }                                                                       \
 174   }
 175 #define LOOP_NEED_FLAGS
 176 #define EXTRA_LOOP_DECLS        , int *curcsp
 177 #define INIT_PARAMS             int curcs = *curcsp & ~7
 178 #define UPDATE_PARAMS           *curcsp = curcs
 179 #include <iconv/loop.c>
 180
 181 /* Next, define the other direction.  */
 182 #define MIN_NEEDED_INPUT        TO_LOOP_MIN_NEEDED_FROM
 183 #define MAX_NEEDED_INPUT        TO_LOOP_MAX_NEEDED_FROM
 184 #define MIN_NEEDED_OUTPUT       TO_LOOP_MIN_NEEDED_TO
 185 #define MAX_NEEDED_OUTPUT       TO_LOOP_MAX_NEEDED_TO
 186 #define LOOPFCT                 TO_LOOP
 187 #define BODY \
 188   {                                                                           \
 189     uint32_t ch = get32 (inptr);                                              \
 190     const struct gap *rp1 = __ucs4_to_ibm935sb_idx;                           \
 191     const struct gap *rp2 = __ucs4_to_ibm935db_idx;                           \
 192                                                                               \
 193     if (__glibc_unlikely (ch >= 0xffff))                                      \
 194       {                                                                       \
 195         UNICODE_TAG_HANDLER (ch, 4);                                          \
 196                                                                               \
 197         STANDARD_TO_LOOP_ERR_HANDLER (4);                                     \
 198       }                                                                       \
 199                                                                               \
 200     while (ch > rp1->end)                                                     \
 201       ++rp1;                                                                  \
 202                                                                               \
 203     /* Use the UCS4 table for single byte.  */                                \
 204     unsigned char sbconv;                                                     \
 205     if (__builtin_expect (ch < rp1->start, 0)                                 \
 206         || (sbconv = __ucs4_to_ibm935sb[ch + rp1->idx],                       \
 207             __builtin_expect (sbconv, L'\1') == L'\0' && ch != '\0'))         \
 208       {                                                                       \
 209         /* Use the UCS4 table for double byte. */                             \
 210         while (ch > rp2->end)                                                 \
 211           ++rp2;                                                              \
 212                                                                               \
 213         const char *cp;                                                       \
 214         if (__builtin_expect (ch < rp2->start, 0)                             \
 215             || (cp = __ucs4_to_ibm935db[ch + rp2->idx],                       \
 216                 __builtin_expect (cp[0], L'\1')==L'\0' && ch != '\0'))        \
 217           {                                                                   \
 218             /* This is an illegal character.  */                              \
 219             STANDARD_TO_LOOP_ERR_HANDLER (4);                                 \
 220           }                                                                   \
 221         else                                                                  \
 222           {                                                                   \
 223             if (curcs == sb)                                                  \
 224               {                                                               \
 225                 if (__glibc_unlikely (outptr + 1 > outend))                   \
 226                   {                                                           \
 227                     result = __GCONV_FULL_OUTPUT;                             \
 228                     break;                                                    \
 229                   }                                                           \
 230                 *outptr++ = SO;                                               \
 231                 curcs = db;                                                   \
 232               }                                                               \
 233                                                                               \
 234             if (__glibc_unlikely (outptr + 2 > outend))                       \
 235               {                                                               \
 236                 result = __GCONV_FULL_OUTPUT;                                 \
 237                 break;                                                        \
 238               }                                                               \
 239             *outptr++ = cp[0];                                                \
 240             *outptr++ = cp[1];                                                \
 241           }                                                                   \
 242       }                                                                       \
 243     else                                                                      \
 244       {                                                                       \
 245         if (curcs == db)                                                      \
 246           {                                                                   \
 247             if (__glibc_unlikely (outptr + 1 > outend))                       \
 248               {                                                               \
 249                 result = __GCONV_FULL_OUTPUT;                                 \
 250                 break;                                                        \
 251               }                                                               \
 252             *outptr++ = SI;                                                   \
 253             curcs = sb;                                                       \
 254           }                                                                   \
 255                                                                               \
 256         if (__glibc_unlikely (outptr + 1 > outend))                           \
 257           {                                                                   \
 258             result = __GCONV_FULL_OUTPUT;                                     \
 259             break;                                                            \
 260           }                                                                   \
 261         *outptr++ = sbconv;                                                   \
 262       }                                                                       \
 263                                                                               \
 264     /* Now that we wrote the output increment the input pointer.  */          \
 265     inptr += 4;                                                               \
 266   }
 267 #define LOOP_NEED_FLAGS
 268 #define EXTRA_LOOP_DECLS        , int *curcsp
 269 #define INIT_PARAMS             int curcs = *curcsp & ~7
 270 #define REINIT_PARAMS           curcs = *curcsp & ~7
 271 #define UPDATE_PARAMS           *curcsp = curcs
 272 #include <iconv/loop.c>
 273
 274 /* Now define the toplevel functions.  */
 275 #include <iconv/skeleton.c>