diff options
Diffstat (limited to 'lib/mbrtowc-impl.h')
| -rw-r--r-- | lib/mbrtowc-impl.h | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/lib/mbrtowc-impl.h b/lib/mbrtowc-impl.h new file mode 100644 index 0000000..65538e7 --- /dev/null +++ b/lib/mbrtowc-impl.h @@ -0,0 +1,262 @@ +/* Convert multibyte character to wide character. + Copyright (C) 1999-2002, 2005-2022 Free Software Foundation, Inc. + + 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/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2008. */ + +/* This file contains the body of the mbrtowc and mbrtoc32 functions, + when GNULIB_defined_mbstate_t is defined. */ + + char *pstate = (char *)ps; + + if (s == NULL) + { + pwc = NULL; + s = ""; + n = 1; + } + + if (n == 0) + return (size_t)(-2); + + /* Here n > 0. */ + + if (pstate == NULL) + pstate = internal_state; + + { + size_t nstate = pstate[0]; + char buf[4]; + const char *p; + size_t m; + enc_t enc; + int res; + + switch (nstate) + { + case 0: + p = s; + m = n; + break; + case 3: + buf[2] = pstate[3]; + FALLTHROUGH; + case 2: + buf[1] = pstate[2]; + FALLTHROUGH; + case 1: + buf[0] = pstate[1]; + p = buf; + m = nstate; + buf[m++] = s[0]; + if (n >= 2 && m < 4) + { + buf[m++] = s[1]; + if (n >= 3 && m < 4) + buf[m++] = s[2]; + } + break; + default: + errno = EINVAL; + return (size_t)(-1); + } + + /* Here m > 0. */ + + enc = locale_encoding_classification (); + + if (enc == enc_utf8) /* UTF-8 */ + { + /* Achieve + - multi-thread safety and + - the ability to produce wide character values > WCHAR_MAX + by not calling mbtowc() at all. */ +#include "mbrtowc-impl-utf8.h" + } + else + { + /* The hidden internal state of mbtowc would make this function not + multi-thread safe. Achieve multi-thread safety through a lock. */ + wchar_t wc; + res = mbtowc_with_lock (&wc, p, m); + + if (res >= 0) + { + if ((wc == 0) != (res == 0)) + abort (); + if (pwc != NULL) + *pwc = wc; + goto success; + } + + /* mbtowc does not distinguish between invalid and incomplete multibyte + sequences. But mbrtowc needs to make this distinction. + There are two possible approaches: + - Use iconv() and its return value. + - Use built-in knowledge about the possible encodings. + Given the low quality of implementation of iconv() on the systems + that lack mbrtowc(), we use the second approach. + The possible encodings are: + - 8-bit encodings, + - EUC-JP, EUC-KR, GB2312, EUC-TW, BIG5, GB18030, SJIS, + - UTF-8 (already handled above). + Use specialized code for each. */ + if (m >= 4 || m >= MB_CUR_MAX) + goto invalid; + /* Here MB_CUR_MAX > 1 and 0 < m < 4. */ + switch (enc) + { + /* As a reference for this code, you can use the GNU libiconv + implementation. Look for uses of the RET_TOOFEW macro. */ + + case enc_eucjp: /* EUC-JP */ + { + if (m == 1) + { + unsigned char c = (unsigned char) p[0]; + + if ((c >= 0xa1 && c < 0xff) || c == 0x8e || c == 0x8f) + goto incomplete; + } + if (m == 2) + { + unsigned char c = (unsigned char) p[0]; + + if (c == 0x8f) + { + unsigned char c2 = (unsigned char) p[1]; + + if (c2 >= 0xa1 && c2 < 0xff) + goto incomplete; + } + } + goto invalid; + } + + case enc_94: /* EUC-KR, GB2312, BIG5 */ + { + if (m == 1) + { + unsigned char c = (unsigned char) p[0]; + + if (c >= 0xa1 && c < 0xff) + goto incomplete; + } + goto invalid; + } + + case enc_euctw: /* EUC-TW */ + { + if (m == 1) + { + unsigned char c = (unsigned char) p[0]; + + if ((c >= 0xa1 && c < 0xff) || c == 0x8e) + goto incomplete; + } + else /* m == 2 || m == 3 */ + { + unsigned char c = (unsigned char) p[0]; + + if (c == 0x8e) + goto incomplete; + } + goto invalid; + } + + case enc_gb18030: /* GB18030 */ + { + if (m == 1) + { + unsigned char c = (unsigned char) p[0]; + + if ((c >= 0x90 && c <= 0xe3) || (c >= 0xf8 && c <= 0xfe)) + goto incomplete; + } + else /* m == 2 || m == 3 */ + { + unsigned char c = (unsigned char) p[0]; + + if (c >= 0x90 && c <= 0xe3) + { + unsigned char c2 = (unsigned char) p[1]; + + if (c2 >= 0x30 && c2 <= 0x39) + { + if (m == 2) + goto incomplete; + else /* m == 3 */ + { + unsigned char c3 = (unsigned char) p[2]; + + if (c3 >= 0x81 && c3 <= 0xfe) + goto incomplete; + } + } + } + } + goto invalid; + } + + case enc_sjis: /* SJIS */ + { + if (m == 1) + { + unsigned char c = (unsigned char) p[0]; + + if ((c >= 0x81 && c <= 0x9f) || (c >= 0xe0 && c <= 0xea) + || (c >= 0xf0 && c <= 0xf9)) + goto incomplete; + } + goto invalid; + } + + default: + /* An unknown multibyte encoding. */ + goto incomplete; + } + } + + success: + /* res >= 0 is the corrected return value of + mbtowc_with_lock (&wc, p, m). */ + if (nstate >= (res > 0 ? res : 1)) + abort (); + res -= nstate; + pstate[0] = 0; + return res; + + incomplete: + { + size_t k = nstate; + /* Here 0 <= k < m < 4. */ + pstate[++k] = s[0]; + if (k < m) + { + pstate[++k] = s[1]; + if (k < m) + pstate[++k] = s[2]; + } + if (k != m) + abort (); + } + pstate[0] = m; + return (size_t)(-2); + + invalid: + errno = EILSEQ; + /* The conversion state is undefined, says POSIX. */ + return (size_t)(-1); + } |