1 /* Store a character in UTF-8 string.
2 Copyright (C) 2002, 2005-2006, 2009-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2002.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file 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
13 GNU 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 #if defined IN_LIBUNISTRING
21 /* Tell unistr.h to declare u8_uctomb as 'extern', not 'static inline'. */
22 # include "unistring-notinline.h"
23 #endif
24
25 /* Specification. */
26 #include "unistr.h"
27
28 #include "attribute.h"
29
30 #if !HAVE_INLINE
31
32 int
u8_uctomb(uint8_t * s,ucs4_t uc,ptrdiff_t n)33 u8_uctomb (uint8_t *s, ucs4_t uc, ptrdiff_t n)
34 {
35 if (uc < 0x80)
36 {
37 if (n > 0)
38 {
39 s[0] = uc;
40 return 1;
41 }
42 /* else return -2, below. */
43 }
44 else
45 {
46 int count;
47
48 if (uc < 0x800)
49 count = 2;
50 else if (uc < 0x10000)
51 {
52 if (uc < 0xd800 || uc >= 0xe000)
53 count = 3;
54 else
55 return -1;
56 }
57 else if (uc < 0x110000)
58 count = 4;
59 else
60 return -1;
61
62 if (n >= count)
63 {
64 switch (count) /* note: code falls through cases! */
65 {
66 case 4: s[3] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x10000;
67 FALLTHROUGH;
68 case 3: s[2] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0x800;
69 FALLTHROUGH;
70 case 2: s[1] = 0x80 | (uc & 0x3f); uc = uc >> 6; uc |= 0xc0;
71 /*case 1:*/ s[0] = uc;
72 }
73 return count;
74 }
75 }
76 return -2;
77 }
78
79 #endif
80