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-rw-r--r--lib/mbrtowc.c458
1 files changed, 458 insertions, 0 deletions
diff --git a/lib/mbrtowc.c b/lib/mbrtowc.c
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+/* Convert multibyte character to wide character.
+ Copyright (C) 1999-2002, 2005-2018 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 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 <https://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <wchar.h>
+
+#if C_LOCALE_MAYBE_EILSEQ
+# include "hard-locale.h"
+# include <locale.h>
+#endif
+
+#if GNULIB_defined_mbstate_t
+/* Implement mbrtowc() on top of mbtowc(). */
+
+# include <errno.h>
+# include <stdlib.h>
+
+# include "localcharset.h"
+# include "streq.h"
+# include "verify.h"
+
+# ifndef FALLTHROUGH
+# if __GNUC__ < 7
+# define FALLTHROUGH ((void) 0)
+# else
+# define FALLTHROUGH __attribute__ ((__fallthrough__))
+# endif
+# endif
+
+/* Returns a classification of special values of the encoding of the current
+ locale. */
+typedef enum {
+ enc_other, /* other */
+ enc_utf8, /* UTF-8 */
+ enc_eucjp, /* EUC-JP */
+ enc_94, /* EUC-KR, GB2312, BIG5 */
+ enc_euctw, /* EUC-TW */
+ enc_gb18030, /* GB18030 */
+ enc_sjis /* SJIS */
+} enc_t;
+static inline enc_t
+locale_enc (void)
+{
+ const char *encoding = locale_charset ();
+ if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
+ return enc_utf8;
+ if (STREQ_OPT (encoding, "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0))
+ return enc_eucjp;
+ if (STREQ_OPT (encoding, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
+ || STREQ_OPT (encoding, "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 0)
+ || STREQ_OPT (encoding, "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0))
+ return enc_94;
+ if (STREQ_OPT (encoding, "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0))
+ return enc_euctw;
+ if (STREQ_OPT (encoding, "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 0))
+ return enc_gb18030;
+ if (STREQ_OPT (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0))
+ return enc_sjis;
+ return enc_other;
+}
+
+#if GNULIB_WCHAR_SINGLE
+/* When we know that the locale does not change, provide a speedup by
+ caching the value of locale_enc. */
+static int cached_locale_enc = -1;
+static inline enc_t
+locale_enc_cached (void)
+{
+ if (cached_locale_enc < 0)
+ cached_locale_enc = locale_enc ();
+ return cached_locale_enc;
+}
+#else
+/* By default, don't make assumptions, hence no caching. */
+# define locale_enc_cached locale_enc
+#endif
+
+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 (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;
+
+ 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__ || defined __UCLIBC__
+ /* Work around bug <https://sourceware.org/bugzilla/show_bug.cgi?id=9674> */
+ 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. */
+ switch (locale_enc_cached ())
+ {
+ case enc_utf8: /* UTF-8 */
+ {
+ /* 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. */
+
+ 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;
+ }
+
+ 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)
+{
+ size_t ret;
+ wchar_t wc;
+
+# if MBRTOWC_NULL_ARG2_BUG || MBRTOWC_RETVAL_BUG || MBRTOWC_EMPTY_INPUT_BUG
+ if (s == NULL)
+ {
+ pwc = NULL;
+ s = "";
+ n = 1;
+ }
+# endif
+
+# if MBRTOWC_EMPTY_INPUT_BUG
+ if (n == 0)
+ return (size_t) -2;
+# endif
+
+ if (! pwc)
+ pwc = &wc;
+
+# if MBRTOWC_RETVAL_BUG
+ {
+ static mbstate_t internal_state;
+
+ /* Override mbrtowc's internal state. We cannot 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--)
+ {
+ 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. */
+ *pwc = wc;
+ return (wc == 0 ? 0 : count);
+ }
+ }
+ return (size_t)(-2);
+ }
+ }
+# endif
+
+ ret = mbrtowc (pwc, s, n, ps);
+
+# if MBRTOWC_NUL_RETVAL_BUG
+ if (ret < (size_t) -2 && !*pwc)
+ return 0;
+# endif
+
+# if C_LOCALE_MAYBE_EILSEQ
+ if ((size_t) -2 <= ret && n != 0 && ! hard_locale (LC_CTYPE))
+ {
+ unsigned char uc = *s;
+ *pwc = uc;
+ return 1;
+ }
+# endif
+
+ return ret;
+}
+
+#endif
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