/src/libunistring/lib/unistr/u8-check.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* Check UTF-8 string. |
2 | | Copyright (C) 2002, 2006-2007, 2009-2023 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 | | /* Specification. */ |
21 | | #include "unistr.h" |
22 | | |
23 | | const uint8_t * |
24 | | u8_check (const uint8_t *s, size_t n) |
25 | 0 | { |
26 | 0 | const uint8_t *s_end = s + n; |
27 | |
|
28 | 0 | while (s < s_end) |
29 | 0 | { |
30 | | /* Keep in sync with unistr.h and u8-mbtouc-aux.c. */ |
31 | 0 | uint8_t c = *s; |
32 | |
|
33 | 0 | if (c < 0x80) |
34 | 0 | { |
35 | 0 | s++; |
36 | 0 | continue; |
37 | 0 | } |
38 | 0 | if (c >= 0xc2) |
39 | 0 | { |
40 | 0 | if (c < 0xe0) |
41 | 0 | { |
42 | 0 | if (s + 2 <= s_end |
43 | 0 | && (s[1] ^ 0x80) < 0x40) |
44 | 0 | { |
45 | 0 | s += 2; |
46 | 0 | continue; |
47 | 0 | } |
48 | 0 | } |
49 | 0 | else if (c < 0xf0) |
50 | 0 | { |
51 | 0 | if (s + 3 <= s_end |
52 | 0 | && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 |
53 | 0 | && (c >= 0xe1 || s[1] >= 0xa0) |
54 | 0 | && (c != 0xed || s[1] < 0xa0)) |
55 | 0 | { |
56 | 0 | s += 3; |
57 | 0 | continue; |
58 | 0 | } |
59 | 0 | } |
60 | 0 | else if (c < 0xf8) |
61 | 0 | { |
62 | 0 | if (s + 4 <= s_end |
63 | 0 | && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40 |
64 | 0 | && (s[3] ^ 0x80) < 0x40 |
65 | 0 | && (c >= 0xf1 || s[1] >= 0x90) |
66 | 0 | && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))) |
67 | 0 | { |
68 | 0 | s += 4; |
69 | 0 | continue; |
70 | 0 | } |
71 | 0 | } |
72 | 0 | } |
73 | | /* invalid or incomplete multibyte character */ |
74 | 0 | return s; |
75 | 0 | } |
76 | 0 | return NULL; |
77 | 0 | } |