1  /* Access functions for JISX0212 conversion.
       2     Copyright (C) 1997-2023 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  #ifndef _JIS0212_H
      20  #define _JIS0212_H	1
      21  
      22  #include <assert.h>
      23  #include <gconv.h>
      24  #include <stdint.h>
      25  
      26  
      27  /* Struct for table with indices in mapping table.  */
      28  struct jisx0212_idx
      29  {
      30    uint16_t start;
      31    uint16_t end;
      32    uint16_t idx;
      33  };
      34  
      35  /* Conversion table.  */
      36  extern const struct jisx0212_idx __jisx0212_to_ucs_idx[];
      37  extern const uint16_t __jisx0212_to_ucs[];
      38  
      39  extern const struct jisx0212_idx __jisx0212_from_ucs_idx[];
      40  extern const char __jisx0212_from_ucs[][2];
      41  
      42  
      43  static inline uint32_t
      44  __attribute ((always_inline))
      45  jisx0212_to_ucs4 (const unsigned char **s, size_t avail, unsigned char offset)
      46  {
      47    const struct jisx0212_idx *rp = __jisx0212_to_ucs_idx;
      48    unsigned char ch = *(*s);
      49    unsigned char ch2;
      50    uint32_t wch = 0;
      51    int idx;
      52  
      53    if (ch < offset || (ch - offset) < 0x22 || (ch - offset) > 0x6d)
      54      return __UNKNOWN_10646_CHAR;
      55  
      56    if (avail < 2)
      57      return 0;
      58  
      59    ch2 = (*s)[1];
      60    if (ch2 < offset || (ch2 - offset) <= 0x20 || (ch2 - offset) >= 0x7f)
      61      return __UNKNOWN_10646_CHAR;
      62  
      63    idx = (ch - offset - 0x21) * 94 + (ch2 - offset - 0x21);
      64  
      65    while (idx > rp->end)
      66      ++rp;
      67    if (idx >= rp->start)
      68      wch = __jisx0212_to_ucs[rp->idx + idx - rp->start];
      69  
      70    if (wch != L'\0')
      71      (*s) += 2;
      72    else
      73      wch = __UNKNOWN_10646_CHAR;
      74  
      75    return wch;
      76  }
      77  
      78  
      79  static inline size_t
      80  __attribute ((always_inline))
      81  ucs4_to_jisx0212 (uint32_t wch, unsigned char *s, size_t avail)
      82  {
      83    const struct jisx0212_idx *rp = __jisx0212_from_ucs_idx;
      84    unsigned int ch = (unsigned int) wch;
      85    const char *cp;
      86  
      87    if (ch >= 0xffff)
      88      return __UNKNOWN_10646_CHAR;
      89    while (ch > rp->end)
      90      ++rp;
      91    if (ch >= rp->start)
      92      cp = __jisx0212_from_ucs[rp->idx + ch - rp->start];
      93    else
      94      return __UNKNOWN_10646_CHAR;
      95  
      96    if (cp[0] == '\0')
      97      return __UNKNOWN_10646_CHAR;
      98  
      99    s[0] = cp[0];
     100    assert (cp[1] != '\0');
     101    if (avail < 2)
     102      return 0;
     103  
     104    s[1] = cp[1];
     105    return 2;
     106  }
     107  
     108  #endif /* jis0212.h */