gnu/dist/gettext/gettext-tools/lib/utf8-ucs4.h

   1 /* Conversion UTF-8 to UCS-4.
   2    Copyright (C) 2001-2002 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 This program 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
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19
  20 #include <stddef.h>
  21
  22 /* Return the length (number of units) of the first character in S, putting
  23    its 'ucs4_t' representation in *PUC.  */
  24 static int
  25 u8_mbtouc_aux (unsigned int *puc, const unsigned char *s, size_t n)
  26 {
  27   unsigned char c = *s;
  28
  29   if (c >= 0xc2)
  30     {
  31       if (c < 0xe0)
  32         {
  33           if (n >= 2)
  34             {
  35               if ((s[1] ^ 0x80) < 0x40)
  36                 {
  37                   *puc = ((unsigned int) (c & 0x1f) << 6)
  38                          | (unsigned int) (s[1] ^ 0x80);
  39                   return 2;
  40                 }
  41               /* invalid multibyte character */
  42             }
  43           else
  44             {
  45               /* incomplete multibyte character */
  46               *puc = 0xfffd;
  47               return n;
  48             }
  49         }
  50       else if (c < 0xf0)
  51         {
  52           if (n >= 3)
  53             {
  54               if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
  55                   && (c >= 0xe1 || s[1] >= 0xa0))
  56                 {
  57                   *puc = ((unsigned int) (c & 0x0f) << 12)
  58                          | ((unsigned int) (s[1] ^ 0x80) << 6)
  59                          | (unsigned int) (s[2] ^ 0x80);
  60                   return 3;
  61                 }
  62               /* invalid multibyte character */
  63             }
  64           else
  65             {
  66               /* incomplete multibyte character */
  67               *puc = 0xfffd;
  68               return n;
  69             }
  70         }
  71       else if (c < 0xf8)
  72         {
  73           if (n >= 4)
  74             {
  75               if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
  76                   && (s[3] ^ 0x80) < 0x40
  77                   && (c >= 0xf1 || s[1] >= 0x90)
  78 #if 1
  79                   && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))
  80 #endif
  81                  )
  82                 {
  83                   *puc = ((unsigned int) (c & 0x07) << 18)
  84                          | ((unsigned int) (s[1] ^ 0x80) << 12)
  85                          | ((unsigned int) (s[2] ^ 0x80) << 6)
  86                          | (unsigned int) (s[3] ^ 0x80);
  87                   return 4;
  88                 }
  89               /* invalid multibyte character */
  90             }
  91           else
  92             {
  93               /* incomplete multibyte character */
  94               *puc = 0xfffd;
  95               return n;
  96             }
  97         }
  98 #if 0
  99       else if (c < 0xfc)
 100         {
 101           if (n >= 5)
 102             {
 103               if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
 104                   && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
 105                   && (c >= 0xf9 || s[1] >= 0x88))
 106                 {
 107                   *puc = ((unsigned int) (c & 0x03) << 24)
 108                          | ((unsigned int) (s[1] ^ 0x80) << 18)
 109                          | ((unsigned int) (s[2] ^ 0x80) << 12)
 110                          | ((unsigned int) (s[3] ^ 0x80) << 6)
 111                          | (unsigned int) (s[4] ^ 0x80);
 112                   return 5;
 113                 }
 114               /* invalid multibyte character */
 115             }
 116           else
 117             {
 118               /* incomplete multibyte character */
 119               *puc = 0xfffd;
 120               return n;
 121             }
 122         }
 123       else if (c < 0xfe)
 124         {
 125           if (n >= 6)
 126             {
 127               if ((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
 128                   && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
 129                   && (s[5] ^ 0x80) < 0x40
 130                   && (c >= 0xfd || s[1] >= 0x84))
 131                 {
 132                   *puc = ((unsigned int) (c & 0x01) << 30)
 133                          | ((unsigned int) (s[1] ^ 0x80) << 24)
 134                          | ((unsigned int) (s[2] ^ 0x80) << 18)
 135                          | ((unsigned int) (s[3] ^ 0x80) << 12)
 136                          | ((unsigned int) (s[4] ^ 0x80) << 6)
 137                          | (unsigned int) (s[5] ^ 0x80);
 138                   return 6;
 139                 }
 140               /* invalid multibyte character */
 141             }
 142           else
 143             {
 144               /* incomplete multibyte character */
 145               *puc = 0xfffd;
 146               return n;
 147             }
 148         }
 149 #endif
 150     }
 151   /* invalid multibyte character */
 152   *puc = 0xfffd;
 153   return 1;
 154 }
 155 static inline int
 156 u8_mbtouc (unsigned int *puc, const unsigned char *s, size_t n)
 157 {
 158   unsigned char c = *s;
 159
 160   if (c < 0x80)
 161     {
 162       *puc = c;
 163       return 1;
 164     }
 165   else
 166     return u8_mbtouc_aux (puc, s, n);
 167 }