1 files changed, 349 insertions, 0 deletions

diff --git a/gl/mbrtowc.c b/gl/mbrtowc.c
new file mode 100644
index 00000000..603f0060
--- /dev/null
+++ b/gl/mbrtowc.c
@@ -0,0 +1,349 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 1999-2002, 2005-2008 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 <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#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"
+
+
+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 0 < m ≤ 4.  */
+
+# if __GLIBC__
+    /* Work around bug <http://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, 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, "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)
+          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