X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=lib%2Fmbrtowc.c;fp=lib%2Fmbrtowc.c;h=0fec5f1c9fac3c67af2fde58774c55b44bd97dcf;hb=c7e61475680fa226bd9b8bdd469cd66914e630f5;hp=0000000000000000000000000000000000000000;hpb=800deb09b422a73c1212233a93839a223ff59678;p=debian%2Fgzip diff --git a/lib/mbrtowc.c b/lib/mbrtowc.c new file mode 100644 index 0000000..0fec5f1 --- /dev/null +++ b/lib/mbrtowc.c @@ -0,0 +1,386 @@ +/* Convert multibyte character to wide character. + Copyright (C) 1999-2002, 2005-2009 Free Software Foundation, Inc. + Written by Bruno Haible , 2008. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include + +/* Specification. */ +#include + +#if GNULIB_defined_mbstate_t +/* Implement mbrtowc() on top of mbtowc(). */ + +# include +# include + +# include "localcharset.h" +# include "streq.h" +# include "verify.h" + + +verify (sizeof (mbstate_t) >= 4); + +static char internal_state[4]; + +size_t +mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps) +{ + char *pstate = (char *)ps; + + if (pstate == NULL) + pstate = internal_state; + + if (s == NULL) + { + pwc = NULL; + s = ""; + n = 1; + } + + if (n == 0) + return (size_t)(-2); + + /* Here n > 0. */ + { + size_t nstate = pstate[0]; + char buf[4]; + const char *p; + size_t m; + + 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. */ + +# if __GLIBC__ + /* Work around bug */ + mbtowc (NULL, NULL, 0); +# endif + { + int res = mbtowc (pwc, p, m); + + if (res >= 0) + { + if (pwc != NULL && ((*pwc == 0) != (res == 0))) + abort (); + if (nstate >= (res > 0 ? res : 1)) + abort (); + res -= nstate; + pstate[0] = 0; + return res; + } + + /* 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. + Use specialized code for each. */ + if (m >= 4 || m >= MB_CUR_MAX) + goto invalid; + /* Here MB_CUR_MAX > 1 and 0 < m < 4. */ + { + const char *encoding = locale_charset (); + + if (STREQ (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0)) + { + /* Cf. unistr/u8-mblen.c. */ + unsigned char c = (unsigned char) p[0]; + + if (c >= 0xc2) + { + if (c < 0xe0) + { + if (m == 1) + goto incomplete; + } + else if (c < 0xf0) + { + if (m == 1) + goto incomplete; + if (m == 2) + { + unsigned char c2 = (unsigned char) p[1]; + + if ((c2 ^ 0x80) < 0x40 + && (c >= 0xe1 || c2 >= 0xa0) + && (c != 0xed || c2 < 0xa0)) + goto incomplete; + } + } + else if (c <= 0xf4) + { + if (m == 1) + goto incomplete; + else /* m == 2 || m == 3 */ + { + unsigned char c2 = (unsigned char) p[1]; + + if ((c2 ^ 0x80) < 0x40 + && (c >= 0xf1 || c2 >= 0x90) + && (c < 0xf4 || (c == 0xf4 && c2 < 0x90))) + { + if (m == 2) + goto incomplete; + else /* m == 3 */ + { + unsigned char c3 = (unsigned char) p[2]; + + if ((c3 ^ 0x80) < 0x40) + goto incomplete; + } + } + } + } + } + goto invalid; + } + + /* As a reference for this code, you can use the GNU libiconv + implementation. Look for uses of the RET_TOOFEW macro. */ + + if (STREQ (encoding, "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0)) + { + 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; + } + if (STREQ (encoding, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0) + || STREQ (encoding, "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 0) + || STREQ (encoding, "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0)) + { + if (m == 1) + { + unsigned char c = (unsigned char) p[0]; + + if (c >= 0xa1 && c < 0xff) + goto incomplete; + } + goto invalid; + } + if (STREQ (encoding, "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0)) + { + 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; + } + if (STREQ (encoding, "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 0)) + { + 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; + } + if (STREQ (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0)) + { + 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; + } + + /* An unknown multibyte encoding. */ + goto incomplete; + } + + 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); + } + } +} + +#else +/* Override the system's mbrtowc() function. */ + +# undef mbrtowc + +size_t +rpl_mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps) +{ +# if MBRTOWC_NULL_ARG_BUG || MBRTOWC_RETVAL_BUG + if (s == NULL) + { + pwc = NULL; + s = ""; + n = 1; + } +# endif + +# if MBRTOWC_RETVAL_BUG + { + static mbstate_t internal_state; + + /* Override mbrtowc's internal state. We can not call mbsinit() on the + hidden internal state, but we can call it on our variable. */ + if (ps == NULL) + ps = &internal_state; + + if (!mbsinit (ps)) + { + /* Parse the rest of the multibyte character byte for byte. */ + size_t count = 0; + for (; n > 0; s++, n--) + { + wchar_t wc; + size_t ret = mbrtowc (&wc, s, 1, ps); + + if (ret == (size_t)(-1)) + return (size_t)(-1); + count++; + if (ret != (size_t)(-2)) + { + /* The multibyte character has been completed. */ + if (pwc != NULL) + *pwc = wc; + return (wc == 0 ? 0 : count); + } + } + return (size_t)(-2); + } + } +# endif + +# if MBRTOWC_NUL_RETVAL_BUG + { + wchar_t wc; + size_t ret = mbrtowc (&wc, s, n, ps); + + if (ret != (size_t)(-1) && ret != (size_t)(-2)) + { + if (pwc != NULL) + *pwc = wc; + if (wc == 0) + ret = 0; + } + return ret; + } +# else + return mbrtowc (pwc, s, n, ps); +# endif +} + +#endif