Line data Source code
1 : /* Conversion UCS-4 to UTF-8.
2 : Copyright (C) 2002, 2006-2007, 2009-2020 Free Software Foundation, Inc.
3 : Written by Bruno Haible <bruno@clisp.org>, 2002.
4 :
5 : This program is free software: you can redistribute it and/or modify it
6 : under the terms of the GNU Lesser General Public License as published
7 : by the Free Software Foundation; either version 2.1 of the License, or
8 : (at your option) 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 GNU
13 : Lesser General Public License for more details.
14 :
15 : You should have received a copy of the GNU Lesser General Public License
16 : along with this program. If not, see <https://www.gnu.org/licenses/>. */
17 :
18 : #include <config.h>
19 :
20 : /* Specification. */
21 : #include "unistr.h"
22 :
23 : #include "attribute.h"
24 :
25 : int
26 165 : u8_uctomb_aux (uint8_t *s, ucs4_t uc, int n)
27 : {
28 : int count;
29 :
30 165 : if (uc < 0x80)
31 : /* The case n >= 1 is already handled by the caller. */
32 128 : return -2;
33 37 : else if (uc < 0x800)
34 3 : count = 2;
35 34 : else if (uc < 0x10000)
36 : {
37 24 : if (uc < 0xd800 || uc >= 0xe000)
38 4 : count = 3;
39 : else
40 20 : return -1;
41 : }
42 10 : else if (uc < 0x110000)
43 5 : count = 4;
44 : else
45 5 : return -1;
46 :
47 12 : if (n < count)
48 9 : return -2;
49 :
50 3 : switch (count) /* note: code falls through cases! */
51 : {
52 1 : case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
53 : FALLTHROUGH;
54 2 : case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
55 : FALLTHROUGH;
56 3 : case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
57 3 : /*case 1:*/ s[0] = uc;
58 : }
59 3 : return count;
60 : }
|