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8bcca1db | 1 | /* UTF-8 to multibyte conversion. |
6d7e8eda | 2 | Copyright (C) 2022-2023 Free Software Foundation, Inc. |
8bcca1db TH |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library 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 GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <https://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include <errno.h> | |
20 | #include <uchar.h> | |
21 | #include <wchar.h> | |
22 | ||
23 | ||
24 | /* This is the private state used if PS is NULL. */ | |
25 | static mbstate_t state; | |
26 | ||
27 | size_t | |
28 | c8rtomb (char *s, char8_t c8, mbstate_t *ps) | |
29 | { | |
30 | /* This implementation depends on the converter invoked by wcrtomb not | |
31 | needing to retain state in either the top most bit of ps->__count or | |
32 | in ps->__value between invocations. This implementation uses the | |
33 | top most bit of ps->__count to indicate that trailing code units are | |
34 | expected and uses ps->__value to store previously seen code units. */ | |
35 | ||
36 | wchar_t wc; | |
37 | ||
38 | if (ps == NULL) | |
39 | ps = &state; | |
40 | ||
41 | if (s == NULL) | |
42 | { | |
43 | /* if 's' is a null pointer, behave as if u8'\0' was passed as 'c8'. If | |
44 | this occurs for an incomplete code unit sequence, then an error will | |
45 | be reported below. */ | |
46 | c8 = u8""[0]; | |
47 | } | |
48 | ||
49 | if (! (ps->__count & 0x80000000)) | |
50 | { | |
51 | /* Initial state. */ | |
52 | if ((c8 >= 0x80 && c8 <= 0xC1) || c8 >= 0xF5) | |
53 | { | |
54 | /* An invalid lead code unit. */ | |
55 | __set_errno (EILSEQ); | |
56 | return -1; | |
57 | } | |
58 | if (c8 >= 0xC2) | |
59 | { | |
60 | /* A valid lead code unit. */ | |
61 | ps->__count |= 0x80000000; | |
62 | ps->__value.__wchb[0] = c8; | |
63 | ps->__value.__wchb[3] = 1; | |
64 | return 0; | |
65 | } | |
66 | /* A single byte (ASCII) code unit. */ | |
67 | wc = c8; | |
68 | } | |
69 | else | |
70 | { | |
71 | char8_t cu1 = ps->__value.__wchb[0]; | |
72 | if (ps->__value.__wchb[3] == 1) | |
73 | { | |
74 | /* A single lead code unit was previously seen. */ | |
75 | if ((c8 < 0x80 || c8 > 0xBF) | |
76 | || (cu1 == 0xE0 && c8 < 0xA0) | |
77 | || (cu1 == 0xED && c8 > 0x9F) | |
78 | || (cu1 == 0xF0 && c8 < 0x90) | |
79 | || (cu1 == 0xF4 && c8 > 0x8F)) | |
80 | { | |
81 | /* An invalid second code unit. */ | |
82 | __set_errno (EILSEQ); | |
83 | return -1; | |
84 | } | |
85 | if (cu1 >= 0xE0) | |
86 | { | |
87 | /* A three or four code unit sequence. */ | |
88 | ps->__value.__wchb[1] = c8; | |
89 | ++ps->__value.__wchb[3]; | |
90 | return 0; | |
91 | } | |
92 | wc = ((cu1 & 0x1F) << 6) | |
93 | + (c8 & 0x3F); | |
94 | } | |
95 | else | |
96 | { | |
97 | char8_t cu2 = ps->__value.__wchb[1]; | |
98 | /* A three or four byte code unit sequence. */ | |
99 | if (c8 < 0x80 || c8 > 0xBF) | |
100 | { | |
101 | /* An invalid third or fourth code unit. */ | |
102 | __set_errno (EILSEQ); | |
103 | return -1; | |
104 | } | |
105 | if (ps->__value.__wchb[3] == 2 && cu1 >= 0xF0) | |
106 | { | |
107 | /* A four code unit sequence. */ | |
108 | ps->__value.__wchb[2] = c8; | |
109 | ++ps->__value.__wchb[3]; | |
110 | return 0; | |
111 | } | |
112 | if (cu1 < 0xF0) | |
113 | { | |
114 | wc = ((cu1 & 0x0F) << 12) | |
115 | + ((cu2 & 0x3F) << 6) | |
116 | + (c8 & 0x3F); | |
117 | } | |
118 | else | |
119 | { | |
120 | char8_t cu3 = ps->__value.__wchb[2]; | |
121 | wc = ((cu1 & 0x07) << 18) | |
122 | + ((cu2 & 0x3F) << 12) | |
123 | + ((cu3 & 0x3F) << 6) | |
124 | + (c8 & 0x3F); | |
125 | } | |
126 | } | |
127 | ps->__count &= 0x7fffffff; | |
128 | ps->__value.__wch = 0; | |
129 | } | |
130 | ||
131 | return wcrtomb (s, wc, ps); | |
132 | } |