iconvdata/ibm937.c

   1 /* Conversion from and to IBM937.
   2    Copyright (C) 2000-2023 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 /* IBM937 is designed for the representation of Traditional Chinese
  20    using a stateful EBCDIC encoding scheme.  It is also known as
  21    CCSID 937 or CP937. See:
  22    https://www-01.ibm.com/software/globalization/ccsid/ccsid937.html */
  23
  24 #include <dlfcn.h>
  25 #include <stdint.h>
  26 #include <wchar.h>
  27 #include <byteswap.h>
  28 #include "ibm937.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    "IBM937//"
  36 #define FROM_LOOP       from_ibm937
  37 #define TO_LOOP         to_ibm937
  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 restore 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-937 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 IBM937 table for single byte.  */                          \
 127         res = __ibm937sb_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 = __ibm937db_to_ucs4_idx;                       \
 143                                                                               \
 144         assert (curcs == db);                                                 \
 145                                                                               \
 146         /* Use the IBM937 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 = __ibm937db_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_ibm937sb_idx;                           \
 191     const struct gap *rp2 = __ucs4_to_ibm937db_idx;                           \
 192     const char *cp;                                                           \
 193                                                                               \
 194     if (__glibc_unlikely (ch >= 0xffff))                                      \
 195       {                                                                       \
 196         UNICODE_TAG_HANDLER (ch, 4);                                          \
 197                                                                               \
 198         STANDARD_TO_LOOP_ERR_HANDLER (4);                                     \
 199       }                                                                       \
 200                                                                               \
 201     while (ch > rp1->end)                                                     \
 202       ++rp1;                                                                  \
 203                                                                               \
 204     /* Use the UCS4 table for single byte.  */                                \
 205     if (__builtin_expect (ch < rp1->start, 0)                                 \
 206         || (cp = __ucs4_to_ibm937sb[ch + rp1->idx],                           \
 207             __builtin_expect (cp[0], L'\1') == L'\0' && ch != '\0'))          \
 208       {                                                                       \
 209         /* Use the UCS4 table for double byte. */                             \
 210         while (ch > rp2->end)                                                 \
 211           ++rp2;                                                              \
 212                                                                               \
 213         if (__builtin_expect (ch < rp2->start, 0)                             \
 214             || (cp = __ucs4_to_ibm937db[ch + rp2->idx],                       \
 215                 __builtin_expect (cp[0], L'\1')==L'\0' && ch != '\0'))        \
 216           {                                                                   \
 217             /* This is an illegal character.  */                              \
 218             STANDARD_TO_LOOP_ERR_HANDLER (4);                                 \
 219           }                                                                   \
 220         else                                                                  \
 221           {                                                                   \
 222             if (curcs == sb)                                                  \
 223               {                                                               \
 224                 if (__glibc_unlikely (outptr + 1 > outend))                   \
 225                   {                                                           \
 226                     result = __GCONV_FULL_OUTPUT;                             \
 227                     break;                                                    \
 228                   }                                                           \
 229                 *outptr++ = SO;                                               \
 230                 curcs = db;                                                   \
 231               }                                                               \
 232                                                                               \
 233             if (__glibc_unlikely (outptr + 2 > outend))                       \
 234               {                                                               \
 235                 result = __GCONV_FULL_OUTPUT;                                 \
 236                 break;                                                        \
 237               }                                                               \
 238             *outptr++ = cp[0];                                                \
 239             *outptr++ = cp[1];                                                \
 240           }                                                                   \
 241       }                                                                       \
 242     else                                                                      \
 243       {                                                                       \
 244         if (curcs == db)                                                      \
 245           {                                                                   \
 246             if (__glibc_unlikely (outptr + 1 > outend))                       \
 247               {                                                               \
 248                 result = __GCONV_FULL_OUTPUT;                                 \
 249                 break;                                                        \
 250               }                                                               \
 251             *outptr++ = SI;                                                   \
 252             curcs = sb;                                                       \
 253           }                                                                   \
 254                                                                               \
 255         if (__glibc_unlikely (outptr + 1 > outend))                           \
 256           {                                                                   \
 257             result = __GCONV_FULL_OUTPUT;                                     \
 258             break;                                                            \
 259           }                                                                   \
 260         *outptr++ = cp[0];                                                    \
 261       }                                                                       \
 262                                                                               \
 263     /* Now that we wrote the output increment the input pointer.  */          \
 264     inptr += 4;                                                               \
 265   }
 266 #define LOOP_NEED_FLAGS
 267 #define EXTRA_LOOP_DECLS        , int *curcsp
 268 #define INIT_PARAMS             int curcs = *curcsp & ~7
 269 #define REINIT_PARAMS           curcs = *curcsp & ~7
 270 #define UPDATE_PARAMS           *curcsp = curcs
 271 #include <iconv/loop.c>
 272
 273 /* Now define the toplevel functions.  */
 274 #include <iconv/skeleton.c>