1 /* Conversion UCS-4 to UTF-8.
2 Copyright (C) 2002, 2006-2007, 2009-2014 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 3 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 <http://www.gnu.org/licenses/>. */
17
18 #include <config.h>
19
20 /* Specification. */
21 #include "unistr.h"
22
23 int
u8_uctomb_aux(uint8_t * s,ucs4_t uc,int n)24 u8_uctomb_aux (uint8_t *s, ucs4_t uc, int n)
25 {
26 int count;
27
28 if (uc < 0x80)
29 /* The case n >= 1 is already handled by the caller. */
30 return -2;
31 else if (uc < 0x800)
32 count = 2;
33 else if (uc < 0x10000)
34 {
35 if (uc < 0xd800 || uc >= 0xe000)
36 count = 3;
37 else
38 return -1;
39 }
40 #if 0
41 else if (uc < 0x200000)
42 count = 4;
43 else if (uc < 0x4000000)
44 count = 5;
45 else if (uc <= 0x7fffffff)
46 count = 6;
47 #else
48 else if (uc < 0x110000)
49 count = 4;
50 #endif
51 else
52 return -1;
53
54 if (n < count)
55 return -2;
56
57 switch (count) /* note: code falls through cases! */
58 {
59 #if 0
60 case 6: s[5] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x4000000;
61 case 5: s[4] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x200000;
62 #endif
63 case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
64 case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
65 case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
66 /*case 1:*/ s[0] = uc;
67 }
68 return count;
69 }
70