/* Multibyte to UTF-8 conversion. Copyright (C) 2022-2024 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> #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; }