Annotation of embedaddon/libiconv/lib/utf16.h, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (C) 1999-2001, 2008 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, write to the Free Software Foundation, Inc., 51 Franklin Street,
! 18: * Fifth Floor, Boston, MA 02110-1301, USA.
! 19: */
! 20:
! 21: /*
! 22: * UTF-16
! 23: */
! 24:
! 25: /* Specification: RFC 2781 */
! 26:
! 27: /* Here we accept FFFE/FEFF marks as endianness indicators everywhere
! 28: in the stream, not just at the beginning. (This is contrary to what
! 29: RFC 2781 section 3.2 specifies, but it allows concatenation of byte
! 30: sequences to work flawlessly, while disagreeing with the RFC behaviour
! 31: only for strings containing U+FEFF characters, which is quite rare.)
! 32: The default is big-endian. */
! 33: /* The state is 0 if big-endian, 1 if little-endian. */
! 34: static int
! 35: utf16_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
! 36: {
! 37: state_t state = conv->istate;
! 38: int count = 0;
! 39: for (; n >= 2;) {
! 40: ucs4_t wc = (state ? s[0] + (s[1] << 8) : (s[0] << 8) + s[1]);
! 41: if (wc == 0xfeff) {
! 42: } else if (wc == 0xfffe) {
! 43: state ^= 1;
! 44: } else if (wc >= 0xd800 && wc < 0xdc00) {
! 45: if (n >= 4) {
! 46: ucs4_t wc2 = (state ? s[2] + (s[3] << 8) : (s[2] << 8) + s[3]);
! 47: if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
! 48: goto ilseq;
! 49: *pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
! 50: conv->istate = state;
! 51: return count+4;
! 52: } else
! 53: break;
! 54: } else if (wc >= 0xdc00 && wc < 0xe000) {
! 55: goto ilseq;
! 56: } else {
! 57: *pwc = wc;
! 58: conv->istate = state;
! 59: return count+2;
! 60: }
! 61: s += 2; n -= 2; count += 2;
! 62: }
! 63: conv->istate = state;
! 64: return RET_TOOFEW(count);
! 65:
! 66: ilseq:
! 67: conv->istate = state;
! 68: return RET_SHIFT_ILSEQ(count);
! 69: }
! 70:
! 71: /* We output UTF-16 in big-endian order, with byte-order mark.
! 72: See RFC 2781 section 3.3 for a rationale: Some document formats
! 73: mandate a BOM; the file concatenation issue is not so severe as
! 74: long as the above utf16_mbtowc function is used. */
! 75: /* The state is 0 at the beginning, 1 after the BOM has been written. */
! 76: static int
! 77: utf16_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
! 78: {
! 79: if (wc != 0xfffe && !(wc >= 0xd800 && wc < 0xe000)) {
! 80: int count = 0;
! 81: if (!conv->ostate) {
! 82: if (n >= 2) {
! 83: r[0] = 0xFE;
! 84: r[1] = 0xFF;
! 85: r += 2; n -= 2; count += 2;
! 86: } else
! 87: return RET_TOOSMALL;
! 88: }
! 89: if (wc < 0x10000) {
! 90: if (n >= 2) {
! 91: r[0] = (unsigned char) (wc >> 8);
! 92: r[1] = (unsigned char) wc;
! 93: conv->ostate = 1;
! 94: return count+2;
! 95: } else
! 96: return RET_TOOSMALL;
! 97: }
! 98: else if (wc < 0x110000) {
! 99: if (n >= 4) {
! 100: ucs4_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
! 101: ucs4_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
! 102: r[0] = (unsigned char) (wc1 >> 8);
! 103: r[1] = (unsigned char) wc1;
! 104: r[2] = (unsigned char) (wc2 >> 8);
! 105: r[3] = (unsigned char) wc2;
! 106: conv->ostate = 1;
! 107: return count+4;
! 108: } else
! 109: return RET_TOOSMALL;
! 110: }
! 111: }
! 112: return RET_ILUNI;
! 113: }
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