timespec_get: New module.
[gnulib.git] / lib / mbsnrtowcs-impl.h
blob50f42f621d2d4e0a4daf42772897f7a6167fcf88
1 /* Convert string to wide string.
2 Copyright (C) 2008-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2008.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program 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 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
18 size_t
19 FUNC (DCHAR_T *dest, const char **srcp, size_t srclen, size_t len, mbstate_t *ps)
21 if (ps == NULL)
22 ps = &INTERNAL_STATE;
24 const char *src = *srcp;
26 if (dest != NULL)
28 DCHAR_T *destptr = dest;
30 for (; srclen > 0 && len > 0; destptr++, len--)
32 size_t src_avail;
33 size_t ret;
35 /* An optimized variant of
36 src_avail = strnlen1 (src, MIN (srclen, MB_LEN_MAX)); */
37 if (srclen == 1 || src[0] == '\0')
38 src_avail = 1;
39 else if (srclen == 2 || src[1] == '\0')
40 src_avail = 2;
41 else if (srclen == 3 || src[2] == '\0')
42 src_avail = 3;
43 else if (MB_LEN_MAX <= 4 || srclen == 4 || src[3] == '\0')
44 src_avail = 4;
45 else
46 src_avail = 4 + strnlen1 (src + 4, MIN (srclen, MB_LEN_MAX) - 4);
48 /* Parse the next multibyte character. */
49 ret = MBRTOWC (destptr, src, src_avail, ps);
51 if (ret == (size_t)(-2))
52 /* Encountered a multibyte character that extends past a '\0' byte
53 or that is longer than MB_LEN_MAX bytes. Cannot happen. */
54 abort ();
56 if (ret == (size_t)(-1))
57 goto bad_input;
58 if (ret == 0)
60 src = NULL;
61 /* Here mbsinit (ps). */
62 break;
64 src += ret;
65 srclen -= ret;
68 *srcp = src;
69 return destptr - dest;
71 else
73 /* Ignore dest and len, don't store *srcp at the end, and
74 don't clobber *ps. */
75 mbstate_t state = *ps;
76 size_t totalcount = 0;
78 for (; srclen > 0; totalcount++)
80 size_t src_avail;
81 size_t ret;
83 /* An optimized variant of
84 src_avail = strnlen1 (src, MIN (srclen, MB_LEN_MAX)); */
85 if (srclen == 1 || src[0] == '\0')
86 src_avail = 1;
87 else if (srclen == 2 || src[1] == '\0')
88 src_avail = 2;
89 else if (srclen == 3 || src[2] == '\0')
90 src_avail = 3;
91 else if (MB_LEN_MAX <= 4 || srclen == 4 || src[3] == '\0')
92 src_avail = 4;
93 else
94 src_avail = 4 + strnlen1 (src + 4, MIN (srclen, MB_LEN_MAX) - 4);
96 /* Parse the next multibyte character. */
97 ret = MBRTOWC (NULL, src, src_avail, &state);
99 if (ret == (size_t)(-2))
100 /* Encountered a multibyte character that extends past a '\0' byte
101 or that is longer than MB_LEN_MAX bytes. Cannot happen. */
102 abort ();
104 if (ret == (size_t)(-1))
105 goto bad_input2;
106 if (ret == 0)
108 /* Here mbsinit (&state). */
109 break;
111 src += ret;
112 srclen -= ret;
115 return totalcount;
118 bad_input:
119 *srcp = src;
120 bad_input2:
121 errno = EILSEQ;
122 return (size_t)(-1);