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78178bb0 RC |
1 | /* |
2 | * charset conversion utils | |
3 | * | |
4 | * Copyright (c) 2017 Rob Clark | |
5 | * | |
6 | * SPDX-License-Identifier: GPL-2.0+ | |
7 | */ | |
8 | ||
78178bb0 RC |
9 | #include <charset.h> |
10 | #include <malloc.h> | |
11 | ||
12 | /* | |
13 | * utf8/utf16 conversion mostly lifted from grub | |
14 | */ | |
15 | ||
16 | size_t utf16_strlen(const uint16_t *in) | |
17 | { | |
18 | size_t i; | |
19 | for (i = 0; in[i]; i++); | |
20 | return i; | |
21 | } | |
22 | ||
23 | size_t utf16_strnlen(const uint16_t *in, size_t count) | |
24 | { | |
25 | size_t i; | |
26 | for (i = 0; count-- && in[i]; i++); | |
27 | return i; | |
28 | } | |
29 | ||
30 | uint16_t *utf16_strcpy(uint16_t *dest, const uint16_t *src) | |
31 | { | |
32 | uint16_t *tmp = dest; | |
33 | ||
34 | while ((*dest++ = *src++) != '\0') | |
35 | /* nothing */; | |
36 | return tmp; | |
37 | ||
38 | } | |
39 | ||
40 | uint16_t *utf16_strdup(const uint16_t *s) | |
41 | { | |
42 | uint16_t *new; | |
43 | if (!s || !(new = malloc((utf16_strlen(s) + 1) * 2))) | |
44 | return NULL; | |
45 | utf16_strcpy(new, s); | |
46 | return new; | |
47 | } | |
48 | ||
49 | /* Convert UTF-16 to UTF-8. */ | |
50 | uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size) | |
51 | { | |
52 | uint32_t code_high = 0; | |
53 | ||
54 | while (size--) { | |
55 | uint32_t code = *src++; | |
56 | ||
57 | if (code_high) { | |
58 | if (code >= 0xDC00 && code <= 0xDFFF) { | |
59 | /* Surrogate pair. */ | |
60 | code = ((code_high - 0xD800) << 10) + (code - 0xDC00) + 0x10000; | |
61 | ||
62 | *dest++ = (code >> 18) | 0xF0; | |
63 | *dest++ = ((code >> 12) & 0x3F) | 0x80; | |
64 | *dest++ = ((code >> 6) & 0x3F) | 0x80; | |
65 | *dest++ = (code & 0x3F) | 0x80; | |
66 | } else { | |
67 | /* Error... */ | |
68 | *dest++ = '?'; | |
69 | /* *src may be valid. Don't eat it. */ | |
70 | src--; | |
71 | } | |
72 | ||
73 | code_high = 0; | |
74 | } else { | |
75 | if (code <= 0x007F) { | |
76 | *dest++ = code; | |
77 | } else if (code <= 0x07FF) { | |
78 | *dest++ = (code >> 6) | 0xC0; | |
79 | *dest++ = (code & 0x3F) | 0x80; | |
80 | } else if (code >= 0xD800 && code <= 0xDBFF) { | |
81 | code_high = code; | |
82 | continue; | |
83 | } else if (code >= 0xDC00 && code <= 0xDFFF) { | |
84 | /* Error... */ | |
85 | *dest++ = '?'; | |
86 | } else if (code < 0x10000) { | |
87 | *dest++ = (code >> 12) | 0xE0; | |
88 | *dest++ = ((code >> 6) & 0x3F) | 0x80; | |
89 | *dest++ = (code & 0x3F) | 0x80; | |
90 | } else { | |
91 | *dest++ = (code >> 18) | 0xF0; | |
92 | *dest++ = ((code >> 12) & 0x3F) | 0x80; | |
93 | *dest++ = ((code >> 6) & 0x3F) | 0x80; | |
94 | *dest++ = (code & 0x3F) | 0x80; | |
95 | } | |
96 | } | |
97 | } | |
98 | ||
99 | return dest; | |
100 | } | |
f58c5ecb HS |
101 | |
102 | uint16_t *utf8_to_utf16(uint16_t *dest, const uint8_t *src, size_t size) | |
103 | { | |
104 | while (size--) { | |
105 | int extension_bytes; | |
106 | uint32_t code; | |
107 | ||
108 | extension_bytes = 0; | |
109 | if (*src <= 0x7f) { | |
110 | code = *src++; | |
111 | /* Exit on zero byte */ | |
112 | if (!code) | |
113 | size = 0; | |
114 | } else if (*src <= 0xbf) { | |
115 | /* Illegal code */ | |
116 | code = '?'; | |
117 | } else if (*src <= 0xdf) { | |
118 | code = *src++ & 0x1f; | |
119 | extension_bytes = 1; | |
120 | } else if (*src <= 0xef) { | |
121 | code = *src++ & 0x0f; | |
122 | extension_bytes = 2; | |
123 | } else if (*src <= 0xf7) { | |
124 | code = *src++ & 0x07; | |
125 | extension_bytes = 3; | |
126 | } else { | |
127 | /* Illegal code */ | |
128 | code = '?'; | |
129 | } | |
130 | ||
131 | for (; extension_bytes && size; --size, --extension_bytes) { | |
132 | if ((*src & 0xc0) == 0x80) { | |
133 | code <<= 6; | |
134 | code |= *src++ & 0x3f; | |
135 | } else { | |
136 | /* Illegal code */ | |
137 | code = '?'; | |
138 | ++src; | |
139 | --size; | |
140 | break; | |
141 | } | |
142 | } | |
143 | ||
144 | if (code < 0x10000) { | |
145 | *dest++ = code; | |
146 | } else { | |
147 | /* | |
148 | * Simplified expression for | |
149 | * (((code - 0x10000) >> 10) & 0x3ff) | 0xd800 | |
150 | */ | |
151 | *dest++ = (code >> 10) + 0xd7c0; | |
152 | *dest++ = (code & 0x3ff) | 0xdc00; | |
153 | } | |
154 | } | |
155 | return dest; | |
156 | } |