iconvdata/cns11643l2.h

   1 /* Access functions for CNS 11643, plane 2 handling.
   2    Copyright (C) 1998-2024 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 #include <stdint.h>
  20 #include <gconv.h>
  21
  22 /* Table for CNS 11643, plane 2 to UCS4 conversion.  */
  23 extern const uint16_t __cns11643l2_to_ucs4_tab[];
  24
  25
  26 static inline uint32_t
  27 __attribute ((always_inline))
  28 cns11643l2_to_ucs4 (const unsigned char **s, size_t avail,
  29                     unsigned char offset)
  30 {
  31   unsigned char ch = *(*s);
  32   unsigned char ch2;
  33   int idx;
  34
  35   if (ch < offset || (ch - offset) <= 0x20 || (ch - offset) > 0x7d)
  36     return __UNKNOWN_10646_CHAR;
  37
  38   if (avail < 2)
  39     return 0;
  40
  41   ch2 = (*s)[1];
  42   if ((ch2 - offset) <= 0x20 || (ch2 - offset) >= 0x7f)
  43     return __UNKNOWN_10646_CHAR;
  44
  45   idx = (ch - 0x21 - offset) * 94 + (ch2 - 0x21 - offset);
  46   if (idx > 0x1de1)
  47     return __UNKNOWN_10646_CHAR;
  48
  49   (*s) += 2;
  50
  51   return __cns11643l2_to_ucs4_tab[idx] ?: ((*s) -= 2, __UNKNOWN_10646_CHAR);
  52 }
  53
  54
  55 /* The table which contains the CNS 11643 level 2 mappings.  */
  56 extern const char __cns11643_from_ucs4p0_tab[][3];
  57
  58
  59 static inline size_t
  60 __attribute ((always_inline))
  61 ucs4_to_cns11643l2 (uint32_t wch, unsigned char *s, size_t avail)
  62 {
  63   unsigned int ch = (unsigned int) wch;
  64   const char *cp = NULL;
  65
  66   if (ch >= 0x4e07 && ch <= 0x9fa4)
  67     {
  68       cp = __cns11643_from_ucs4p0_tab[ch - 0x3400];
  69       if (cp[0] == '\2')
  70         ++cp;
  71       else
  72         cp = NULL;
  73     }
  74
  75   if (cp == NULL)
  76     return __UNKNOWN_10646_CHAR;
  77
  78   if (avail < 2)
  79     return 0;
  80
  81   s[0] = cp[0];
  82   s[1] = cp[1];
  83
  84   return 2;
  85 }