1/*
2 * Copyright (C) 1999-2001, 2004 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-8
23 */
24
25/* Specification: RFC 3629 */
26
27static int
28utf8_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
29{
30  unsigned char c = s[0];
31
32  if (c < 0x80) {
33    *pwc = c;
34    return 1;
35  } else if (c < 0xc2) {
36    return RET_ILSEQ;
37  } else if (c < 0xe0) {
38    if (n < 2)
39      return RET_TOOFEW(0);
40    if (!((s[1] ^ 0x80) < 0x40))
41      return RET_ILSEQ;
42    *pwc = ((ucs4_t) (c & 0x1f) << 6)
43           | (ucs4_t) (s[1] ^ 0x80);
44    return 2;
45  } else if (c < 0xf0) {
46    if (n < 3)
47      return RET_TOOFEW(0);
48    if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
49          && (c >= 0xe1 || 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      return RET_ILSEQ;
62    *pwc = ((ucs4_t) (c & 0x07) << 18)
63           | ((ucs4_t) (s[1] ^ 0x80) << 12)
64           | ((ucs4_t) (s[2] ^ 0x80) << 6)
65           | (ucs4_t) (s[3] ^ 0x80);
66    return 4;
67  } else if (c < 0xfc && sizeof(ucs4_t)*8 >= 32) {
68    if (n < 5)
69      return RET_TOOFEW(0);
70    if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
71          && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
72          && (c >= 0xf9 || s[1] >= 0x88)))
73      return RET_ILSEQ;
74    *pwc = ((ucs4_t) (c & 0x03) << 24)
75           | ((ucs4_t) (s[1] ^ 0x80) << 18)
76           | ((ucs4_t) (s[2] ^ 0x80) << 12)
77           | ((ucs4_t) (s[3] ^ 0x80) << 6)
78           | (ucs4_t) (s[4] ^ 0x80);
79    return 5;
80  } else if (c < 0xfe && sizeof(ucs4_t)*8 >= 32) {
81    if (n < 6)
82      return RET_TOOFEW(0);
83    if (!((s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
84          && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
85          && (s[5] ^ 0x80) < 0x40
86          && (c >= 0xfd || s[1] >= 0x84)))
87      return RET_ILSEQ;
88    *pwc = ((ucs4_t) (c & 0x01) << 30)
89           | ((ucs4_t) (s[1] ^ 0x80) << 24)
90           | ((ucs4_t) (s[2] ^ 0x80) << 18)
91           | ((ucs4_t) (s[3] ^ 0x80) << 12)
92           | ((ucs4_t) (s[4] ^ 0x80) << 6)
93           | (ucs4_t) (s[5] ^ 0x80);
94    return 6;
95  } else
96    return RET_ILSEQ;
97}
98
99static int
100utf8_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n) /* n == 0 is acceptable */
101{
102  int count;
103  if (wc < 0x80)
104    count = 1;
105  else if (wc < 0x800)
106    count = 2;
107  else if (wc < 0x10000)
108    count = 3;
109  else if (wc < 0x200000)
110    count = 4;
111  else if (wc < 0x4000000)
112    count = 5;
113  else if (wc <= 0x7fffffff)
114    count = 6;
115  else
116    return RET_ILUNI;
117  if (n < count)
118    return RET_TOOSMALL;
119  switch (count) { /* note: code falls through cases! */
120    case 6: r[5] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x4000000;
121    case 5: r[4] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x200000;
122    case 4: r[3] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x10000;
123    case 3: r[2] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0x800;
124    case 2: r[1] = 0x80 | (wc & 0x3f); wc = wc >> 6; wc |= 0xc0;
125    case 1: r[0] = wc;
126  }
127  return count;
128}
129