text: /* Character set conversion.
     Copyright (C) 1999-2001, 2007, 2009-2012 Free Software Foundation, Inc.
  
     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 2, 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 <iconv.h>
  
  #include <stddef.h>
  
  #if REPLACE_ICONV_UTF
  # include <errno.h>
  # include <stdint.h>
  # include <stdlib.h>
  # include "unistr.h"
  # ifndef uintptr_t
  #  define uintptr_t unsigned long
  # endif
  #endif
  
  #if REPLACE_ICONV_UTF
  
  /* UTF-{16,32}{BE,LE} converters taken from GNU libiconv 1.11.  */
  
  /* Return code if invalid. (xxx_mbtowc) */
  # define RET_ILSEQ      -1
  /* Return code if no bytes were read. (xxx_mbtowc) */
  # define RET_TOOFEW     -2
  
  /* Return code if invalid. (xxx_wctomb) */
  # define RET_ILUNI      -1
  /* Return code if output buffer is too small. (xxx_wctomb, xxx_reset) */
  # define RET_TOOSMALL   -2
  
  /*
   * UTF-16BE
   */
  
  /* Specification: RFC 2781 */
  
  static int
  utf16be_mbtowc (ucs4_t *pwc, const unsigned char *s, size_t n)
  {
    if (n >= 2)
      {
        ucs4_t wc = (s[0] << 8) + s[1];
        if (wc >= 0xd800 && wc < 0xdc00)
          {
            if (n >= 4)
              {
                ucs4_t wc2 = (s[2] << 8) + s[3];
                if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
                  return RET_ILSEQ;
                *pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
                return 4;
              }
          }
        else if (wc >= 0xdc00 && wc < 0xe000)
          {
            return RET_ILSEQ;
          }
        else
          {
            *pwc = wc;
            return 2;
          }
      }
    return RET_TOOFEW;
  }
  
  static int
  utf16be_wctomb (unsigned char *r, ucs4_t wc, size_t n)
  {
    if (!(wc >= 0xd800 && wc < 0xe000))
      {
        if (wc < 0x10000)
          {
            if (n >= 2)
              {
                r[0] = (unsigned char) (wc >> 8);
                r[1] = (unsigned char) wc;
                return 2;
              }
            else
              return RET_TOOSMALL;
          }
        else if (wc < 0x110000)
          {
            if (n >= 4)
              {
                ucs4_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
                ucs4_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
                r[0] = (unsigned char) (wc1 >> 8);
                r[1] = (unsigned char) wc1;
                r[2] = (unsigned char) (wc2 >> 8);
                r[3] = (unsigned char) wc2;
                return 4;
              }
            else
              return RET_TOOSMALL;
          }
      }
    return RET_ILUNI;
  }
  
  /*
   * UTF-16LE
   */
  
  /* Specification: RFC 2781 */
  
  static int
  utf16le_mbtowc (ucs4_t *pwc, const unsigned char *s, size_t n)
  {
    if (n >= 2)
      {
        ucs4_t wc = s[0] + (s[1] << 8);
        if (wc >= 0xd800 && wc < 0xdc00)
          {
            if (n >= 4)
              {
                ucs4_t wc2 = s[2] + (s[3] << 8);
                if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
                  return RET_ILSEQ;
                *pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
                return 4;
              }
          }
        else if (wc >= 0xdc00 && wc < 0xe000)
          {
            return RET_ILSEQ;
          }
        else
          {
            *pwc = wc;
            return 2;
          }
      }
    return RET_TOOFEW;
  }
  
  static int
  utf16le_wctomb (unsigned char *r, ucs4_t wc, size_t n)
  {
    if (!(wc >= 0xd800 && wc < 0xe000))
      {
        if (wc < 0x10000)
          {
            if (n >= 2)
              {
                r[0] = (unsigned char) wc;
                r[1] = (unsigned char) (wc >> 8);
                return 2;
              }
            else
              return RET_TOOSMALL;
          }
        else if (wc < 0x110000)
          {
            if (n >= 4)
              {
                ucs4_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
                ucs4_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
                r[0] = (unsigned char) wc1;
                r[1] = (unsigned char) (wc1 >> 8);
                r[2] = (unsigned char) wc2;
                r[3] = (unsigned char) (wc2 >> 8);
                return 4;
              }
            else
              return RET_TOOSMALL;
          }
      }
    return RET_ILUNI;
  }
  
  /*
   * UTF-32BE
   */
  
  /* Specification: Unicode 3.1 Standard Annex #19 */
  
  static int
  utf32be_mbtowc (ucs4_t *pwc, const unsigned char *s, size_t n)
  {
    if (n >= 4)
      {
        ucs4_t wc = (s[0] << 24) + (s[1] << 16) + (s[2] << 8) + s[3];
        if (wc < 0x110000 && !(wc >= 0xd800 && wc < 0xe000))
          {
            *pwc = wc;
            return 4;
          }
        else
          return RET_ILSEQ;
      }
    return RET_TOOFEW;
  }
  
  static int
  utf32be_wctomb (unsigned char *r, ucs4_t wc, size_t n)
  {
    if (wc < 0x110000 && !(wc >= 0xd800 && wc < 0xe000))
      {
        if (n >= 4)
          {
            r[0] = 0;
            r[1] = (unsigned char) (wc >> 16);
            r[2] = (unsigned char) (wc >> 8);
            r[3] = (unsigned char) wc;
            return 4;
          }
        else
          return RET_TOOSMALL;
      }
    return RET_ILUNI;
  }
  
  /*
   * UTF-32LE
   */
  
  /* Specification: Unicode 3.1 Standard Annex #19 */
  
  static int
  utf32le_mbtowc (ucs4_t *pwc, const unsigned char *s, size_t n)
  {
    if (n >= 4)
      {
        ucs4_t wc = s[0] + (s[1] << 8) + (s[2] << 16) + (s[3] << 24);
        if (wc < 0x110000 && !(wc >= 0xd800 && wc < 0xe000))
          {
            *pwc = wc;
            return 4;
          }
        else
          return RET_ILSEQ;
      }
    return RET_TOOFEW;
  }
  
  static int
  utf32le_wctomb (unsigned char *r, ucs4_t wc, size_t n)
  {
    if (wc < 0x110000 && !(wc >= 0xd800 && wc < 0xe000))
      {
        if (n >= 4)
          {
            r[0] = (unsigned char) wc;
            r[1] = (unsigned char) (wc >> 8);
            r[2] = (unsigned char) (wc >> 16);
            r[3] = 0;
            return 4;
          }
        else
          return RET_TOOSMALL;
      }
    return RET_ILUNI;
  }
  
  #endif
  
  size_t
  rpl_iconv (iconv_t cd,
             ICONV_CONST char **inbuf, size_t *inbytesleft,
             char **outbuf, size_t *outbytesleft)
  #undef iconv
  {
  #if REPLACE_ICONV_UTF
    switch ((uintptr_t) cd)
      {
        {
          int (*xxx_wctomb) (unsigned char *, ucs4_t, size_t);
  
          case (uintptr_t) _ICONV_UTF8_UTF16BE:
            xxx_wctomb = utf16be_wctomb;
            goto loop_from_utf8;
          case (uintptr_t) _ICONV_UTF8_UTF16LE:
            xxx_wctomb = utf16le_wctomb;
            goto loop_from_utf8;
          case (uintptr_t) _ICONV_UTF8_UTF32BE:
            xxx_wctomb = utf32be_wctomb;
            goto loop_from_utf8;
          case (uintptr_t) _ICONV_UTF8_UTF32LE:
            xxx_wctomb = utf32le_wctomb;
            goto loop_from_utf8;
  
         loop_from_utf8:
          if (inbuf == NULL || *inbuf == NULL)
            return 0;
          {
            ICONV_CONST char *inptr = *inbuf;
            size_t inleft = *inbytesleft;
            char *outptr = *outbuf;
            size_t outleft = *outbytesleft;
            size_t res = 0;
            while (inleft > 0)
              {
                ucs4_t uc;
                int m = u8_mbtoucr (&uc, (const uint8_t *) inptr, inleft);
                if (m <= 0)
                  {
                    if (m == -1)
                      {
                        errno = EILSEQ;
                        res = (size_t)(-1);
                        break;
                      }
                    if (m == -2)
                      {
                        errno = EINVAL;
                        res = (size_t)(-1);
                        break;
                      }
                    abort ();
                  }
                else
                  {
                    int n = xxx_wctomb ((uint8_t *) outptr, uc, outleft);
                    if (n < 0)
                      {
                        if (n == RET_ILUNI)
                          {
                            errno = EILSEQ;
                            res = (size_t)(-1);
                            break;
                          }
                        if (n == RET_TOOSMALL)
                          {
                            errno = E2BIG;
                            res = (size_t)(-1);
                            break;
                          }
                        abort ();
                      }
                    else
                      {
                        inptr += m;
                        inleft -= m;
                        outptr += n;
                        outleft -= n;
                      }
                  }
              }
            *inbuf = inptr;
            *inbytesleft = inleft;
            *outbuf = outptr;
            *outbytesleft = outleft;
            return res;
          }
        }
  
        {
          int (*xxx_mbtowc) (ucs4_t *, const unsigned char *, size_t);
  
          case (uintptr_t) _ICONV_UTF16BE_UTF8:
            xxx_mbtowc = utf16be_mbtowc;
            goto loop_to_utf8;
          case (uintptr_t) _ICONV_UTF16LE_UTF8:
            xxx_mbtowc = utf16le_mbtowc;
            goto loop_to_utf8;
          case (uintptr_t) _ICONV_UTF32BE_UTF8:
            xxx_mbtowc = utf32be_mbtowc;
            goto loop_to_utf8;
          case (uintptr_t) _ICONV_UTF32LE_UTF8:
            xxx_mbtowc = utf32le_mbtowc;
            goto loop_to_utf8;
  
         loop_to_utf8:
          if (inbuf == NULL || *inbuf == NULL)
            return 0;
          {
            ICONV_CONST char *inptr = *inbuf;
            size_t inleft = *inbytesleft;
            char *outptr = *outbuf;
            size_t outleft = *outbytesleft;
            size_t res = 0;
            while (inleft > 0)
              {
                ucs4_t uc;
                int m = xxx_mbtowc (&uc, (const uint8_t *) inptr, inleft);
                if (m <= 0)
                  {
                    if (m == RET_ILSEQ)
                      {
                        errno = EILSEQ;
                        res = (size_t)(-1);
                        break;
                      }
                    if (m == RET_TOOFEW)
                      {
                        errno = EINVAL;
                        res = (size_t)(-1);
                        break;
                      }
                    abort ();
                  }
                else
                  {
                    int n = u8_uctomb ((uint8_t *) outptr, uc, outleft);
                    if (n < 0)
                      {
                        if (n == -1)
                          {
                            errno = EILSEQ;
                            res = (size_t)(-1);
                            break;
                          }
                        if (n == -2)
                          {
                            errno = E2BIG;
                            res = (size_t)(-1);
                            break;
                          }
                        abort ();
                      }
                    else
                      {
                        inptr += m;
                        inleft -= m;
                        outptr += n;
                        outleft -= n;
                      }
                  }
              }
            *inbuf = inptr;
            *inbytesleft = inleft;
            *outbuf = outptr;
            *outbytesleft = outleft;
            return res;
          }
        }
      }
  #endif
    return iconv (cd, inbuf, inbytesleft, outbuf, outbytesleft);
  }
  