rm_/lib/mbsrtowcs-impl.h
2022-07-28 14:16:50 +08:00

123 lines
3.6 KiB
C

/* Convert string to wide string.
Copyright (C) 2008-2022 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2008.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
size_t
FUNC (DCHAR_T *dest, const char **srcp, size_t len, mbstate_t *ps)
{
if (ps == NULL)
ps = &INTERNAL_STATE;
{
const char *src = *srcp;
if (dest != NULL)
{
DCHAR_T *destptr = dest;
for (; len > 0; destptr++, len--)
{
size_t src_avail;
size_t ret;
/* An optimized variant of
src_avail = strnlen1 (src, MB_LEN_MAX); */
if (src[0] == '\0')
src_avail = 1;
else if (src[1] == '\0')
src_avail = 2;
else if (src[2] == '\0')
src_avail = 3;
else if (MB_LEN_MAX <= 4 || src[3] == '\0')
src_avail = 4;
else
src_avail = 4 + strnlen1 (src + 4, MB_LEN_MAX - 4);
/* Parse the next multibyte character. */
ret = MBRTOWC (destptr, src, src_avail, ps);
if (ret == (size_t)(-2))
/* Encountered a multibyte character that extends past a '\0' byte
or that is longer than MB_LEN_MAX bytes. Cannot happen. */
abort ();
if (ret == (size_t)(-1))
goto bad_input;
if (ret == 0)
{
src = NULL;
/* Here mbsinit (ps). */
break;
}
src += ret;
}
*srcp = src;
return destptr - dest;
}
else
{
/* Ignore dest and len, don't store *srcp at the end, and
don't clobber *ps. */
mbstate_t state = *ps;
size_t totalcount = 0;
for (;; totalcount++)
{
size_t src_avail;
size_t ret;
/* An optimized variant of
src_avail = strnlen1 (src, MB_LEN_MAX); */
if (src[0] == '\0')
src_avail = 1;
else if (src[1] == '\0')
src_avail = 2;
else if (src[2] == '\0')
src_avail = 3;
else if (MB_LEN_MAX <= 4 || src[3] == '\0')
src_avail = 4;
else
src_avail = 4 + strnlen1 (src + 4, MB_LEN_MAX - 4);
/* Parse the next multibyte character. */
ret = MBRTOWC (NULL, src, src_avail, &state);
if (ret == (size_t)(-2))
/* Encountered a multibyte character that extends past a '\0' byte
or that is longer than MB_LEN_MAX bytes. Cannot happen. */
abort ();
if (ret == (size_t)(-1))
goto bad_input2;
if (ret == 0)
{
/* Here mbsinit (&state). */
break;
}
src += ret;
}
return totalcount;
}
bad_input:
*srcp = src;
bad_input2:
errno = EILSEQ;
return (size_t)(-1);
}
}