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libiconv 1.16

    1: /*
    2:  * Copyright (C) 1999-2001, 2004, 2016 Free Software Foundation, Inc.
    3:  * This file is part of the GNU LIBICONV Library.
    4:  *
    5:  * The GNU LIBICONV Library is free software; you can redistribute it
    6:  * and/or modify it under the terms of the GNU Library General Public
    7:  * License as published by the Free Software Foundation; either version 2
    8:  * of the License, or (at your option) any later version.
    9:  *
   10:  * The GNU LIBICONV Library is distributed in the hope that it will be
   11:  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:  * Library General Public License for more details.
   14:  *
   15:  * You should have received a copy of the GNU Library General Public
   16:  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
   17:  * If not, see <https://www.gnu.org/licenses/>.
   18:  */
   19: 
   20: /*
   21:  * UTF-8
   22:  */
   23: 
   24: /* Specification: RFC 3629 */
   25: 
   26: static int
   27: utf8_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n)
   28: {
   29:   unsigned char c = s[0];
   30: 
   31:   if (c < 0x80) {
   32:     *pwc = c;
   33:     return 1;
   34:   } else if (c < 0xc2) {
   35:     return RET_ILSEQ;
   36:   } else if (c < 0xe0) {
   37:     if (n < 2)
   38:       return RET_TOOFEW(0);
   39:     if (!((s[1] ^ 0x80) < 0x40))
   40:       return RET_ILSEQ;
   41:     *pwc = ((ucs4_t) (c & 0x1f) << 6)
   42:            | (ucs4_t) (s[1] ^ 0x80);
   43:     return 2;
   44:   } else if (c < 0xf0) {
   45:     if (n < 3)
   46:       return RET_TOOFEW(0);
   47:     if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
   48:           && (c >= 0xe1 || s[1] >= 0xa0)
   49:           && (c != 0xed || s[1] < 0xa0)))
   50:       return RET_ILSEQ;
   51:     *pwc = ((ucs4_t) (c & 0x0f) << 12)
   52:            | ((ucs4_t) (s[1] ^ 0x80) << 6)
   53:            | (ucs4_t) (s[2] ^ 0x80);
   54:     return 3;
   55:   } else if (c < 0xf8 && sizeof(ucs4_t)*8 >= 32) {
   56:     if (n < 4)
   57:       return RET_TOOFEW(0);
   58:     if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
   59:           && (s[3] ^ 0x80) < 0x40
   60:           && (c >= 0xf1 || s[1] >= 0x90)
   61:           && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))))
   62:       return RET_ILSEQ;
   63:     *pwc = ((ucs4_t) (c & 0x07) << 18)
   64:            | ((ucs4_t) (s[1] ^ 0x80) << 12)
   65:            | ((ucs4_t) (s[2] ^ 0x80) << 6)
   66:            | (ucs4_t) (s[3] ^ 0x80);
   67:     return 4;
   68:   } else
   69:     return RET_ILSEQ;
   70: }
   71: 
   72: static int
   73: utf8_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, size_t n) /* n == 0 is acceptable */
   74: {
   75:   int count;
   76:   if (wc < 0x80)
   77:     count = 1;
   78:   else if (wc < 0x800)
   79:     count = 2;
   80:   else if (wc < 0x10000) {
   81:     if (wc < 0xd800 || wc >= 0xe000)
   82:       count = 3;
   83:     else
   84:       return RET_ILUNI;
   85:   } else if (wc < 0x110000)
   86:     count = 4;
   87:   else
   88:     return RET_ILUNI;
   89:   if (n < count)
   90:     return RET_TOOSMALL;
   91:   switch (count) { /* note: code falls through cases! */
   92:     case 4: r[3] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x10000;
   93:     case 3: r[2] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x800;
   94:     case 2: r[1] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0xc0;
   95:     case 1: r[0] = wc;
   96:   }
   97:   return count;
   98: }