1 files changed, 262 insertions, 0 deletions

diff --git a/gl/mbrtowc-impl.h b/gl/mbrtowc-impl.h
new file mode 100644
index 00000000..e9c04ed7
--- /dev/null
+++ b/gl/mbrtowc-impl.h
@@ -0,0 +1,262 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 1999-2002, 2005-2023 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);
+  }