1/* MIT/X Consortium Copyright (c) 2012 Connor Lane Smith <cls@lubutu.com>
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a
4 * copy of this software and associated documentation files (the "Software"),
5 * to deal in the Software without restriction, including without limitation
6 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
7 * and/or sell copies of the Software, and to permit persons to whom the
8 * Software is furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
16 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
19 * DEALINGS IN THE SOFTWARE.
20 */
21#include "../utf.h"
22
23#define MIN(x, y) ((x) < (y) ? (x) : (y))
24
25#define UTFSEQ(x) \
26 ((((x) & 0x80) == 0x00) ? 1 /* 0xxxxxxx */ \
27 : (((x) & 0xC0) == 0x80) ? 0 /* 10xxxxxx */ \
28 : (((x) & 0xE0) == 0xC0) ? 2 /* 110xxxxx */ \
29 : (((x) & 0xF0) == 0xE0) ? 3 /* 1110xxxx */ \
30 : (((x) & 0xF8) == 0xF0) ? 4 /* 11110xxx */ \
31 : (((x) & 0xFC) == 0xF8) ? 5 /* 111110xx */ \
32 : (((x) & 0xFE) == 0xFC) ? 6 /* 1111110x */ \
33 : 0)
34
35#define BADRUNE(x) \
36 ((x) < 0 || (x) > Runemax || ((x) & 0xFFFE) == 0xFFFE || ((x) >= 0xD800 && (x) <= 0xDFFF) \
37 || ((x) >= 0xFDD0 && (x) <= 0xFDEF))
38
39int
40runetochar(char *s, const Rune *p)
41{
42 Rune r = *p;
43
44 switch (runelen(r)) {
45 case 1: /* 0aaaaaaa */
46 s[0] = r;
47 return 1;
48 case 2: /* 00000aaa aabbbbbb */
49 s[0] = 0xC0 | ((r & 0x0007C0) >> 6); /* 110aaaaa */
50 s[1] = 0x80 | (r & 0x00003F); /* 10bbbbbb */
51 return 2;
52 case 3: /* aaaabbbb bbcccccc */
53 s[0] = 0xE0 | ((r & 0x00F000) >> 12); /* 1110aaaa */
54 s[1] = 0x80 | ((r & 0x000FC0) >> 6); /* 10bbbbbb */
55 s[2] = 0x80 | (r & 0x00003F); /* 10cccccc */
56 return 3;
57 case 4: /* 000aaabb bbbbcccc ccdddddd */
58 s[0] = 0xF0 | ((r & 0x1C0000) >> 18); /* 11110aaa */
59 s[1] = 0x80 | ((r & 0x03F000) >> 12); /* 10bbbbbb */
60 s[2] = 0x80 | ((r & 0x000FC0) >> 6); /* 10cccccc */
61 s[3] = 0x80 | (r & 0x00003F); /* 10dddddd */
62 return 4;
63 default:
64 return 0; /* error */
65 }
66}
67
68int
69chartorune(Rune *p, const char *s)
70{
71 return charntorune(p, s, UTFmax);
72}
73
74int
75charntorune(Rune *p, const char *s, size_t len)
76{
77 unsigned int i, n;
78 Rune r;
79
80 if (len == 0) /* can't even look at s[0] */
81 return 0;
82
83 switch ((n = UTFSEQ(s[0]))) {
84 case 1:
85 r = s[0];
86 break; /* 0xxxxxxx */
87 case 2:
88 r = s[0] & 0x1F;
89 break; /* 110xxxxx */
90 case 3:
91 r = s[0] & 0x0F;
92 break; /* 1110xxxx */
93 case 4:
94 r = s[0] & 0x07;
95 break; /* 11110xxx */
96 case 5:
97 r = s[0] & 0x03;
98 break; /* 111110xx */
99 case 6:
100 r = s[0] & 0x01;
101 break; /* 1111110x */
102 default: /* invalid sequence */
103 *p = Runeerror;
104 return 1;
105 }
106 /* add values from continuation bytes */
107 for (i = 1; i < MIN(n, len); i++)
108 if ((s[i] & 0xC0) == 0x80) {
109 /* add bits from continuation byte to rune value
110 * cannot overflow: 6 byte sequences contain 31 bits */
111 r = (r << 6) | (s[i] & 0x3F); /* 10xxxxxx */
112 } else { /* expected continuation */
113 *p = Runeerror;
114 return i;
115 }
116
117 if (i < n) /* must have reached len limit */
118 return 0;
119
120 /* reject invalid or overlong sequences */
121 if (BADRUNE(r) || runelen(r) < (int)n)
122 r = Runeerror;
123
124 *p = r;
125 return n;
126}
127
128int
129runelen(Rune r)
130{
131 if (BADRUNE(r))
132 return 0; /* error */
133 else if (r <= 0x7F)
134 return 1;
135 else if (r <= 0x07FF)
136 return 2;
137 else if (r <= 0xFFFF)
138 return 3;
139 else
140 return 4;
141}
142
143size_t
144runenlen(const Rune *p, size_t len)
145{
146 size_t i, n = 0;
147
148 for (i = 0; i < len; i++)
149 n += runelen(p[i]);
150 return n;
151}
152
153int
154fullrune(const char *s, size_t len)
155{
156 Rune r;
157
158 return charntorune(&r, s, len) > 0;
159}
