newlib-cygwin/newlib/libc/stdlib/mbtowc_r.c

#include <stdlib.h>
#include <locale.h>
#include "mbctype.h"
#include <wchar.h>
#include <string.h>

#ifdef MB_CAPABLE
typedef enum { ESCAPE, DOLLAR, BRACKET, AT, B, J, 
               NUL, JIS_CHAR, OTHER, JIS_C_NUM } JIS_CHAR_TYPE;
typedef enum { ASCII, A_ESC, A_ESC_DL, JIS, JIS_1, JIS_2, J_ESC, J_ESC_BR,
               J2_ESC, J2_ESC_BR, DONE, INV, JIS_S_NUM } JIS_STATE; 
typedef enum { COPY_A, COPY_J, COPY_J2, MAKE_A, MAKE_J, NOOP, EMPTY, ERROR } JIS_ACTION;

/************************************************************************************** 
 * state/action tables for processing JIS encoding
 * Where possible, switches to JIS are grouped with proceding JIS characters and switches
 * to ASCII are grouped with preceding JIS characters.  Thus, maximum returned length
 * is 2 (switch to JIS) + 2 (JIS characters) + 2 (switch back to ASCII) = 6.
 *************************************************************************************/

static JIS_STATE JIS_state_table[JIS_S_NUM][JIS_C_NUM] = {
/*              ESCAPE   DOLLAR    BRACKET   AT       B       J        NUL      JIS_CHAR  OTHER */
/* ASCII */   { A_ESC,   DONE,     DONE,     DONE,    DONE,   DONE,    DONE,    DONE,     DONE },
/* A_ESC */   { DONE,    A_ESC_DL, DONE,     DONE,    DONE,   DONE,    DONE,    DONE,     DONE },
/* A_ESC_DL */{ DONE,    DONE,     DONE,     JIS,     JIS,    DONE,    DONE,    DONE,     DONE }, 
/* JIS */     { J_ESC,   JIS_1,    JIS_1,    JIS_1,   JIS_1,  JIS_1,   INV,     JIS_1,    INV },
/* JIS_1 */   { INV,     JIS_2,    JIS_2,    JIS_2,   JIS_2,  JIS_2,   INV,     JIS_2,    INV },
/* JIS_2 */   { J2_ESC,  DONE,     DONE,     DONE,    DONE,   DONE,    INV,     DONE,     DONE },
/* J_ESC */   { INV,     INV,      J_ESC_BR, INV,     INV,    INV,     INV,     INV,      INV },
/* J_ESC_BR */{ INV,     INV,      INV,      INV,     ASCII,  ASCII,   INV,     INV,      INV },
/* J2_ESC */  { INV,     INV,      J2_ESC_BR,INV,     INV,    INV,     INV,     INV,      INV },
/* J2_ESC_BR*/{ INV,     INV,      INV,      INV,     DONE,   DONE,    INV,     INV,      INV },
};

static JIS_ACTION JIS_action_table[JIS_S_NUM][JIS_C_NUM] = {
/*              ESCAPE   DOLLAR    BRACKET   AT       B        J        NUL      JIS_CHAR  OTHER */
/* ASCII */   { NOOP,    COPY_A,   COPY_A,   COPY_A,  COPY_A,  COPY_A,  EMPTY,   COPY_A,  COPY_A},
/* A_ESC */   { COPY_A,  NOOP,     COPY_A,   COPY_A,  COPY_A,  COPY_A,  COPY_A,  COPY_A,  COPY_A},
/* A_ESC_DL */{ COPY_A,  COPY_A,   COPY_A,   MAKE_J,  MAKE_J,  COPY_A,  COPY_A,  COPY_A,  COPY_A},
/* JIS */     { NOOP,    NOOP,     NOOP,     NOOP,    NOOP,    NOOP,    ERROR,   NOOP,    ERROR },
/* JIS_1 */   { ERROR,   NOOP,     NOOP,     NOOP,    NOOP,    NOOP,    ERROR,   NOOP,    ERROR },
/* JIS_2 */   { NOOP,    COPY_J2,  COPY_J2,  COPY_J2, COPY_J2, COPY_J2, ERROR,   COPY_J2, COPY_J2},
/* J_ESC */   { ERROR,   ERROR,    NOOP,     ERROR,   ERROR,   ERROR,   ERROR,   ERROR,   ERROR },
/* J_ESC_BR */{ ERROR,   ERROR,    ERROR,    ERROR,   NOOP,    NOOP,    ERROR,   ERROR,   ERROR },
/* J2_ESC */  { ERROR,   ERROR,    NOOP,     ERROR,   ERROR,   ERROR,   ERROR,   ERROR,   ERROR },
/* J2_ESC_BR*/{ ERROR,   ERROR,    ERROR,    ERROR,   COPY_J,  COPY_J,  ERROR,   ERROR,   ERROR },
};
#endif /* MB_CAPABLE */

int
_DEFUN (_mbtowc_r, (r, pwc, s, n, state),
        struct _reent *r   _AND
        wchar_t       *pwc _AND 
        const char    *s   _AND        
        size_t         n   _AND
        mbstate_t      *state)
{
  wchar_t dummy;
  unsigned char *t = (unsigned char *)s;

  if (pwc == NULL)
    pwc = &dummy;

  if (s != NULL && n == 0)
    return -2;

#ifdef MB_CAPABLE
  if (r->_current_locale == NULL ||
      (strlen (r->_current_locale) <= 1))
    { /* fall-through */ }
  else if (!strcmp (r->_current_locale, "C-UTF-8"))
    {
      wchar_t char1 = 0;

      if (s == NULL)
        return 0; /* UTF-8 character encodings are not state-dependent */

      /* we know n >= 1 if we get here */
      *pwc = 0;
      char1 = (wchar_t)*t;

      if (char1 == '\0')
        return 0; /* s points to the null character */

      if (char1 >= 0x0 && char1 <= 0x7f)
        {
          /* single-byte sequence */
          *pwc = char1;
          return 1;
        }
      else if (char1 >= 0xc0 && char1 <= 0xdf)
        {
          /* two-byte sequence */
          if (n >= 2)
            {
              wchar_t char2 = (wchar_t)*(t+1);

              if (char2 < 0x80 || char2 > 0xbf)
                return -1;

              if (char1 < 0xc2)
                /* overlong UTF-8 sequence */
                return -1;

              *pwc = ((char1 & 0x1f) << 6)
                |     (char2 & 0x3f);
              return 2;
            }
          else
            return -1;
        }
      else if (char1 >= 0xe0 && char1 <= 0xef)
        {
          /* three-byte sequence */
          if (n >= 3)
            {
              wchar_t char2 = (wchar_t)*(t+1);
              wchar_t char3 = (wchar_t)*(t+2);

              if (char2 < 0x80 || char2 > 0xbf)
                return -1;
              if (char3 < 0x80 || char3 > 0xbf)
                return -1;

              if (char1 == 0xe0)
                {
                  if (char2 < 0xa0)
                    /* overlong UTF-8 sequence */
                    return -1;
                }

              *pwc = ((char1 & 0x0f) << 12)
                |    ((char2 & 0x3f) << 6)
                |     (char3 & 0x3f);

              if (*pwc >= 0xd800 && *pwc <= 0xdfff)
                {
                  return -1;
                }
              else
                return 3;
            }
          else
            return -2;
        }
      else if (char1 >= 0xf0 && char1 <= 0xf7)
        {
          /* four-byte sequence */
          if (n >= 4)
            {
              wchar_t char2 = (wchar_t)*(t+1);
              wchar_t char3 = (wchar_t)*(t+2);
              wchar_t char4 = (wchar_t)*(t+3);

              if (char2 < 0x80 || char2 > 0xbf)
                return -1;
              if (char3 < 0x80 || char3 > 0xbf)
                return -1;
              if (char4 < 0x80 || char4 > 0xbf)
                return -1;

              if (char1 == 0xf0)
                {
                  if (char2 < 0x90)
                    /* overlong UTF-8 sequence */
                    return -1;
                }
                    
              *pwc = ((char1 & 0x07) << 18)
                |    ((char2 & 0x3f) << 12)
                |    ((char3 & 0x3f) << 6)
                |     (char4 & 0x3f);

              return 4;
            }
          else
            return -2;
        }
      else if (char1 >= 0xf8 && char1 <= 0xfb)
        {
          /* five-byte sequence */
          if (n >= 5)
            {
              wchar_t char2 = (wchar_t)*(t+1);
              wchar_t char3 = (wchar_t)*(t+2);
              wchar_t char4 = (wchar_t)*(t+3);
              wchar_t char5 = (wchar_t)*(t+4);

              if (char2 < 0x80 || char2 > 0xbf)
                return -1;
              if (char3 < 0x80 || char3 > 0xbf)
                return -1;
              if (char4 < 0x80 || char4 > 0xbf)
                return -1;
              if (char5 < 0x80 || char5 > 0xbf)
                return -1;

              if (char1 == 0xf8)
                {
                  if (char2 < 0x88)
                    /* overlong UTF-8 sequence */
                    return -1;
                }
                    
              *pwc = ((char1 & 0x03) << 24)
                |    ((char2 & 0x3f) << 18)
                |    ((char3 & 0x3f) << 12)
                |    ((char4 & 0x3f) << 6)
                |     (char5 & 0x3f);
              return 5;
            }
          else
            return -2;
        }
      else if (char1 >= 0xfc && char1 <= 0xfd)
        {
          /* six-byte sequence */
          if (n >= 6)
            {
              wchar_t char2 = (wchar_t)*(t+1);
              wchar_t char3 = (wchar_t)*(t+2);
              wchar_t char4 = (wchar_t)*(t+3);
              wchar_t char5 = (wchar_t)*(t+4);
              wchar_t char6 = (wchar_t)*(t+5);

              if (char2 < 0x80 || char2 > 0xbf)
                return -1;
              if (char3 < 0x80 || char3 > 0xbf)
                return -1;
              if (char4 < 0x80 || char4 > 0xbf)
                return -1;
              if (char5 < 0x80 || char5 > 0xbf)
                return -1;
              if (char6 < 0x80 || char6 > 0xbf)
                return -1;

              if (char1 == 0xfc)
                {
                  if (char2 < 0x84)
                    /* overlong UTF-8 sequence */
                    return -1;
                }

              *pwc = ((char1 & 0x01) << 30)
                |    ((char2 & 0x3f) << 24)
                |    ((char3 & 0x3f) << 18)
                |    ((char4 & 0x3f) << 12)
                |    ((char5 & 0x3f) << 6)
                |     (char6 & 0x3f);
              return 6;
            }
          else
            return -2;
        }
      else
        return -1;
    }      
  else if (!strcmp (r->_current_locale, "C-SJIS"))
    {
      int char1;
      if (s == NULL)
        return 0;  /* not state-dependent */
      char1 = *t;
      if (_issjis1 (char1))
        {
          int char2 = t[1];
          if (n <= 1)
            return -2;
          if (_issjis2 (char2))
            {
              *pwc = (((wchar_t)*t) << 8) + (wchar_t)(*(t+1));
              return 2;
            }
          else  
            return -1;
        }
    }
  else if (!strcmp (r->_current_locale, "C-EUCJP"))
    {
      int char1;
      if (s == NULL)
        return 0;  /* not state-dependent */
      char1 = *t;
      if (_iseucjp (char1))
        {
          int char2 = t[1];     
          if (n <= 1)
            return -2;
          if (_iseucjp (char2))
            {
              *pwc = (((wchar_t)*t) << 8) + (wchar_t)(*(t+1));
              return 2;
            }
          else
            return -1;
        }
    }
  else if (!strcmp (r->_current_locale, "C-JIS"))
    {
      JIS_STATE curr_state;
      JIS_ACTION action;
      JIS_CHAR_TYPE ch;
      unsigned char *ptr;
      int i, curr_ch;
 
      if (s == NULL)
        {
          state->__count = 0;
          return 1;  /* state-dependent */
        }

      curr_state = (state->__count == 0 ? ASCII : JIS);
      ptr = t;

      for (i = 0; i < n; ++i)
        {
          curr_ch = t[i];
          switch (curr_ch)
            {
	    case ESC_CHAR:
              ch = ESCAPE;
              break;
	    case '$':
              ch = DOLLAR;
              break;
            case '@':
              ch = AT;
              break;
            case '(':
	      ch = BRACKET;
              break;
            case 'B':
              ch = B;
              break;
            case 'J':
              ch = J;
              break;
            case '\0':
              ch = NUL;
              break;
            default:
              if (_isjis (curr_ch))
                ch = JIS_CHAR;
              else
                ch = OTHER;
	    }

          action = JIS_action_table[curr_state][ch];
          curr_state = JIS_state_table[curr_state][ch];
        
          switch (action)
            {
            case NOOP:
              break;
            case EMPTY:
              state->__count = 0;
              *pwc = (wchar_t)0;
              return i;
            case COPY_A:
	      state->__count = 0;
              *pwc = (wchar_t)*ptr;
              return (i + 1);
            case COPY_J:
              state->__count = 0;
              *pwc = (((wchar_t)*ptr) << 8) + (wchar_t)(*(ptr+1));
              return (i + 1);
            case COPY_J2:
              state->__count = 1;
              *pwc = (((wchar_t)*ptr) << 8) + (wchar_t)(*(ptr+1));
              return (ptr - t) + 2;
            case MAKE_A:
            case MAKE_J:
              ptr = (char *)(t + i + 1);
              break;
            case ERROR:
            default:
              return -1;
            }

        }

      return -2;  /* n < bytes needed */
    }
#endif /* MB_CAPABLE */               

  /* otherwise this must be the "C" locale or unknown locale */
  if (s == NULL)
    return 0;  /* not state-dependent */

  *pwc = (wchar_t)*t;
  
  if (*t == '\0')
    return 0;

  return 1;
}