/src/libidn2/gl/unistr/u8-mbtoucr.c
Line | Count | Source |
1 | | /* Look at first character in UTF-8 string, returning an error code. |
2 | | Copyright (C) 1999-2002, 2006-2007, 2009-2025 Free Software Foundation, Inc. |
3 | | Written by Bruno Haible <bruno@clisp.org>, 2001. |
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 | | /* Specification. */ |
21 | | #include "unistr.h" |
22 | | |
23 | | int |
24 | | u8_mbtoucr (ucs4_t *puc, const uint8_t *s, size_t n) |
25 | 14.9k | { |
26 | 14.9k | uint8_t c = *s; |
27 | | |
28 | 14.9k | if (c < 0x80) |
29 | 1.16k | { |
30 | 1.16k | *puc = c; |
31 | 1.16k | return 1; |
32 | 1.16k | } |
33 | 13.7k | else if (c >= 0xc2) |
34 | 13.7k | { |
35 | 13.7k | if (c < 0xe0) |
36 | 4.71k | { |
37 | 4.71k | if (n >= 2) |
38 | 4.71k | { |
39 | 4.71k | if ((s[1] ^ 0x80) < 0x40) |
40 | 4.71k | { |
41 | 4.71k | *puc = ((unsigned int) (c & 0x1f) << 6) |
42 | 4.71k | | (unsigned int) (s[1] ^ 0x80); |
43 | 4.71k | return 2; |
44 | 4.71k | } |
45 | | /* invalid multibyte character */ |
46 | 4.71k | } |
47 | 0 | else |
48 | 0 | { |
49 | | /* incomplete multibyte character */ |
50 | 0 | *puc = 0xfffd; |
51 | 0 | return -2; |
52 | 0 | } |
53 | 4.71k | } |
54 | 9.07k | else if (c < 0xf0) |
55 | 6.76k | { |
56 | 6.76k | if (n >= 2) |
57 | 6.76k | { |
58 | 6.76k | if ((s[1] ^ 0x80) < 0x40 |
59 | 6.76k | && (c >= 0xe1 || s[1] >= 0xa0) |
60 | 6.76k | && (c != 0xed || s[1] < 0xa0)) |
61 | 6.76k | { |
62 | 6.76k | if (n >= 3) |
63 | 6.76k | { |
64 | 6.76k | if ((s[2] ^ 0x80) < 0x40) |
65 | 6.76k | { |
66 | 6.76k | *puc = ((unsigned int) (c & 0x0f) << 12) |
67 | 6.76k | | ((unsigned int) (s[1] ^ 0x80) << 6) |
68 | 6.76k | | (unsigned int) (s[2] ^ 0x80); |
69 | 6.76k | return 3; |
70 | 6.76k | } |
71 | | /* invalid multibyte character */ |
72 | 6.76k | } |
73 | 0 | else |
74 | 0 | { |
75 | | /* incomplete multibyte character */ |
76 | 0 | *puc = 0xfffd; |
77 | 0 | return -2; |
78 | 0 | } |
79 | 6.76k | } |
80 | | /* invalid multibyte character */ |
81 | 6.76k | } |
82 | 0 | else |
83 | 0 | { |
84 | | /* incomplete multibyte character */ |
85 | 0 | *puc = 0xfffd; |
86 | 0 | return -2; |
87 | 0 | } |
88 | 6.76k | } |
89 | 2.31k | else if (c <= 0xf4) |
90 | 2.31k | { |
91 | 2.31k | if (n >= 2) |
92 | 2.31k | { |
93 | 2.31k | if ((s[1] ^ 0x80) < 0x40 |
94 | 2.31k | && (c >= 0xf1 || s[1] >= 0x90) |
95 | 2.31k | && (c < 0xf4 || (/* c == 0xf4 && */ s[1] < 0x90))) |
96 | 2.31k | { |
97 | 2.31k | if (n >= 3) |
98 | 2.31k | { |
99 | 2.31k | if ((s[2] ^ 0x80) < 0x40) |
100 | 2.31k | { |
101 | 2.31k | if (n >= 4) |
102 | 2.31k | { |
103 | 2.31k | if ((s[3] ^ 0x80) < 0x40) |
104 | 2.31k | { |
105 | 2.31k | *puc = ((unsigned int) (c & 0x07) << 18) |
106 | 2.31k | | ((unsigned int) (s[1] ^ 0x80) << 12) |
107 | 2.31k | | ((unsigned int) (s[2] ^ 0x80) << 6) |
108 | 2.31k | | (unsigned int) (s[3] ^ 0x80); |
109 | 2.31k | return 4; |
110 | 2.31k | } |
111 | | /* invalid multibyte character */ |
112 | 2.31k | } |
113 | 0 | else |
114 | 0 | { |
115 | | /* incomplete multibyte character */ |
116 | 0 | *puc = 0xfffd; |
117 | 0 | return -2; |
118 | 0 | } |
119 | 2.31k | } |
120 | | /* invalid multibyte character */ |
121 | 2.31k | } |
122 | 0 | else |
123 | 0 | { |
124 | | /* incomplete multibyte character */ |
125 | 0 | *puc = 0xfffd; |
126 | 0 | return -2; |
127 | 0 | } |
128 | 2.31k | } |
129 | | /* invalid multibyte character */ |
130 | 2.31k | } |
131 | 0 | else |
132 | 0 | { |
133 | | /* incomplete multibyte character */ |
134 | 0 | *puc = 0xfffd; |
135 | 0 | return -2; |
136 | 0 | } |
137 | 2.31k | } |
138 | 13.7k | } |
139 | | /* invalid multibyte character */ |
140 | 0 | *puc = 0xfffd; |
141 | 0 | return -1; |
142 | 14.9k | } |