diff options
Diffstat (limited to 'wcsmbs/mbrtoc8.c')
-rw-r--r-- | wcsmbs/mbrtoc8.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/wcsmbs/mbrtoc8.c b/wcsmbs/mbrtoc8.c new file mode 100644 index 0000000000..dd80b5282d --- /dev/null +++ b/wcsmbs/mbrtoc8.c @@ -0,0 +1,126 @@ +/* Multibyte to UTF-8 conversion. + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library 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. + + The GNU C Library 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 the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <assert.h> +#include <dlfcn.h> +#include <errno.h> +#include <gconv.h> +#include <uchar.h> +#include <wcsmbsload.h> + +#include <sysdep.h> + +#ifndef EILSEQ +# define EILSEQ EINVAL +#endif + + +/* This is the private state used if PS is NULL. */ +static mbstate_t state; + +size_t +mbrtoc8 (char8_t *pc8, const char *s, size_t n, mbstate_t *ps) +{ + /* This implementation depends on the converter invoked by mbrtowc not + needing to retain state in either the top most bit of ps->__count or + in ps->__value between invocations. This implementation uses the + top most bit of ps->__count to indicate that trailing code units are + yet to be written and uses ps->__value to store those code units. */ + + if (ps == NULL) + ps = &state; + + /* If state indicates that trailing code units are yet to be written, write + those first regardless of whether 's' is a null pointer. */ + if (ps->__count & 0x80000000) + { + /* ps->__value.__wchb[3] stores the index of the next code unit to + write. Code units are stored in reverse order. */ + size_t i = ps->__value.__wchb[3]; + if (pc8 != NULL) + { + *pc8 = ps->__value.__wchb[i]; + } + if (i == 0) + { + ps->__count &= 0x7fffffff; + ps->__value.__wch = 0; + } + else + --ps->__value.__wchb[3]; + return -3; + } + + if (s == NULL) + { + /* if 's' is a null pointer, behave as if a null pointer was passed for + 'pc8', an empty string was passed for 's', and 1 passed for 'n'. */ + pc8 = NULL; + s = ""; + n = 1; + } + + wchar_t wc; + size_t result; + + result = mbrtowc (&wc, s, n, ps); + if (result <= n) + { + if (wc <= 0x7F) + { + if (pc8 != NULL) + *pc8 = wc; + } + else if (wc <= 0x7FF) + { + if (pc8 != NULL) + *pc8 = 0xC0 + ((wc >> 6) & 0x1F); + ps->__value.__wchb[0] = 0x80 + (wc & 0x3F); + ps->__value.__wchb[3] = 0; + ps->__count |= 0x80000000; + } + else if (wc <= 0xFFFF) + { + if (pc8 != NULL) + *pc8 = 0xE0 + ((wc >> 12) & 0x0F); + ps->__value.__wchb[1] = 0x80 + ((wc >> 6) & 0x3F); + ps->__value.__wchb[0] = 0x80 + (wc & 0x3F); + ps->__value.__wchb[3] = 1; + ps->__count |= 0x80000000; + } + else if (wc <= 0x10FFFF) + { + if (pc8 != NULL) + *pc8 = 0xF0 + ((wc >> 18) & 0x07); + ps->__value.__wchb[2] = 0x80 + ((wc >> 12) & 0x3F); + ps->__value.__wchb[1] = 0x80 + ((wc >> 6) & 0x3F); + ps->__value.__wchb[0] = 0x80 + (wc & 0x3F); + ps->__value.__wchb[3] = 2; + ps->__count |= 0x80000000; + } + } + if (result == 0 && wc != 0) + { + /* mbrtowc() never returns -3. When a MB sequence converts to multiple + WCs, no input is consumed when writing the subsequent WCs resulting + in a result of 0 even if a null character wasn't written. */ + result = -3; + } + + return result; +} |