wcsmbs/mbrtowc.c

   1 /* Copyright (C) 1996,1997,1998,1999,2000,2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <dlfcn.h>
  21 #include <errno.h>
  22 #include <gconv.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26 #include <assert.h>
  27
  28 #ifndef EILSEQ
  29 # define EILSEQ EINVAL
  30 #endif
  31
  32 #undef __mbrtowc
  33
  34 /* This is the private state used if PS is NULL.  */
  35 static mbstate_t state;
  36
  37 size_t
  38 __mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
  39 {
  40   wchar_t buf[1];
  41   struct __gconv_step_data data;
  42   int status;
  43   size_t result;
  44   size_t dummy;
  45   const unsigned char *inbuf;
  46   char *outbuf = (char *) (pwc ?: buf);
  47
  48   /* Set information for this step.  */
  49   data.__invocation_counter = 0;
  50   data.__internal_use = 1;
  51   data.__flags = __GCONV_IS_LAST;
  52   data.__statep = ps ?: &state;
  53   data.__trans = NULL;
  54
  55   /* A first special case is if S is NULL.  This means put PS in the
  56      initial state.  */
  57   if (s == NULL)
  58     {
  59       outbuf = (char *) buf;
  60       s = "";
  61       n = 1;
  62     }
  63
  64   /* Tell where we want the result.  */
  65   data.__outbuf = outbuf;
  66   data.__outbufend = outbuf + sizeof (wchar_t);
  67
  68   /* Make sure we use the correct function.  */
  69   update_conversion_ptrs ();
  70
  71   /* Do a normal conversion.  */
  72   inbuf = (const unsigned char *) s;
  73   status = DL_CALL_FCT (__wcsmbs_gconv_fcts.towc->__fct,
  74                         (__wcsmbs_gconv_fcts.towc, &data, &inbuf, inbuf + n,
  75                          NULL, &dummy, 0, 1));
  76
  77   /* There must not be any problems with the conversion but illegal input
  78      characters.  The output buffer must be large enough, otherwise the
  79      definition of MB_CUR_MAX is not correct.  All the other possible
  80      errors also must not happen.  */
  81   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  82           || status == __GCONV_ILLEGAL_INPUT
  83           || status == __GCONV_INCOMPLETE_INPUT
  84           || status == __GCONV_FULL_OUTPUT);
  85
  86   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  87       || status == __GCONV_FULL_OUTPUT)
  88     {
  89       if (data.__outbuf != (unsigned char *) outbuf
  90           && *(wchar_t *) outbuf == L'\0')
  91         {
  92           /* The converted character is the NUL character.  */
  93           assert (__mbsinit (data.__statep));
  94           result = 0;
  95         }
  96       else
  97         result = inbuf - (const unsigned char *) s;
  98     }
  99   else if (status == __GCONV_INCOMPLETE_INPUT)
 100     result = (size_t) -2;
 101   else
 102     {
 103       result = (size_t) -1;
 104       __set_errno (EILSEQ);
 105     }
 106
 107   return result;
 108 }
 109 INTDEF(__mbrtowc)
 110 weak_alias (__mbrtowc, mbrtowc)