1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
/* See LICENSE file for copyright and license details. */
#include "libsimple.h"
#ifndef TEST
int
libsimple_isutf8(const char *string, int allow_modified_nul)
{
static long BYTES_TO_MIN_BITS[] = {0, 0, 8, 12, 17, 22, 27};
static long BYTES_TO_MAX_BITS[] = {0, 7, 11, 16, 21, 26, 31};
long int bytes = 0, read_bytes = 0, bits = 0, c, character;
/* min bits max bits
0....... 0 7
110..... 10...... 8 11
1110.... 10...... 10...... 12 16
11110... 10...... 10...... 10...... 17 21
111110.. 10...... 10...... 10...... 10...... 22 26
1111110. 10...... 10...... 10...... 10...... 10...... 27 31
*/
while ((c = (long int)(*string++))) {
if (!read_bytes) {
/* First byte of the character. */
if (!(c & 0x80))
/* Single-byte character. */
continue;
if ((c & 0xC0) == 0x80)
/* Single-byte character marked as multibyte, or
a non-first byte in a multibyte character. */
return 0;
/* Multibyte character. */
while ((c & 0x80))
bytes++, c <<= 1;
read_bytes = 1;
character = (c & 0xFF) >> bytes;
if (bytes > 6)
/* 31-bit characters can be encoded with 6-bytes,
and UTF-8 does not cover higher code points. */
return 0;
} else {
/* Not first byte of the character. */
if ((c & 0xC0) != 0x80)
/* Beginning of new character before a
multibyte character has ended. */
return 0;
character = (character << 6) | (c & 0x7F);
if (++read_bytes < bytes)
/* Not at last byte yet. */
continue;
/* Check that the character is not unnecessarily long. */
while (character)
character >>= 1, bits++;
bits = (!bits && bytes == 2 && allow_modified_nul) ? 8 : bits;
if (bits < BYTES_TO_MIN_BITS[bytes] || BYTES_TO_MAX_BITS[bytes] < bits)
return 0;
read_bytes = bytes = bits = 0;
}
}
/* Make sure we did not stop at the middle of a multibyte character. */
return !read_bytes;
}
#else
#include "test.h"
int
main(void)
{
int i;
for (i = 0; i < 2; i++) {
assert(libsimple_isutf8("", i) == 1);
assert(libsimple_isutf8("a", i) == 1);
assert(libsimple_isutf8("abc", i) == 1);
assert(libsimple_isutf8("123", i) == 1);
assert(libsimple_isutf8("åäö", i) == 1);
assert(libsimple_isutf8("𝖆𝖇𝖈", i) == 1);
assert(libsimple_isutf8("\x1b", i) == 1);
assert(libsimple_isutf8("\n\r\t\f", i) == 1);
assert(libsimple_isutf8("\xFF", i) == 0);
assert(libsimple_isutf8("\x01", i) == 1);
assert(libsimple_isutf8("\x7F", i) == 1);
assert(libsimple_isutf8("\x80", i) == 0);
assert(libsimple_isutf8("\xC0", i) == 0);
assert(libsimple_isutf8("\xC0\x80", i) == i);
assert(libsimple_isutf8("\xC0\x81", i) == 0);
assert(libsimple_isutf8("\xCF", i) == 0);
assert(libsimple_isutf8("\xEF", i) == 0);
assert(libsimple_isutf8("\xEF\x8F", i) == 0);
assert(libsimple_isutf8("\xF7", i) == 0);
assert(libsimple_isutf8("\xF7\x8F", i) == 0);
assert(libsimple_isutf8("\xF7\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFA", i) == 0);
assert(libsimple_isutf8("\xFA\x8F", i) == 0);
assert(libsimple_isutf8("\xFA\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFA\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFD", i) == 0);
assert(libsimple_isutf8("\xFD\x8F", i) == 0);
assert(libsimple_isutf8("\xFD\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFD\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFD\x8F\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFE", i) == 0);
assert(libsimple_isutf8("\xFE\x8F", i) == 0);
assert(libsimple_isutf8("\xFE\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFE\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFE\x8F\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFE\x8F\x8F\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFF", i) == 0);
assert(libsimple_isutf8("\xFF\x8F", i) == 0);
assert(libsimple_isutf8("\xFF\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFF\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFF\x8F\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFF\x8F\x8F\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xFF\x8F\x8F\x8F\x8F\x8F\x8F", i) == 0);
assert(libsimple_isutf8("\xC1\x80", i) == 0);
assert(libsimple_isutf8("\xC2\x80", i) == 1);
assert(libsimple_isutf8("\xE1\x80\x80\x80", i) == 0);
assert(libsimple_isutf8("\xE1\x80\xC0\x80", i) == 0);
assert(libsimple_isutf8("\xE1\x80\x00\x80", i) == 0);
assert(libsimple_isutf8("\xF1\x80\x80\x80", i) == 1);
assert(libsimple_isutf8("\xFF\x80\x80\x80\x80\x80\x80\x80", i) == 0);
}
return 0;
}
#endif
|
