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 /* This is the private state used if PS is NULL.  */
  33 static mbstate_t state;
  34
  35 size_t
  36 __mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
  37 {
  38   wchar_t buf[1];
  39   struct __gconv_step_data data;
  40   int status;
  41   size_t result;
  42   size_t dummy;
  43   const unsigned char *inbuf;
  44   char *outbuf = (char *) (pwc ?: buf);
  45   const struct gconv_fcts *fcts;
  46
  47   /* Set information for this step.  */
  48   data.__invocation_counter = 0;
  49   data.__internal_use = 1;
  50   data.__flags = __GCONV_IS_LAST;
  51   data.__statep = ps ?: &state;
  52   data.__trans = NULL;
  53
  54   /* A first special case is if S is NULL.  This means put PS in the
  55      initial state.  */
  56   if (s == NULL)
  57     {
  58       outbuf = (char *) buf;
  59       s = "";
  60       n = 1;
  61     }
  62
  63   /* Tell where we want the result.  */
  64   data.__outbuf = outbuf;
  65   data.__outbufend = outbuf + sizeof (wchar_t);
  66
  67   /* Get the conversion functions.  */
  68   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  69
  70   /* Do a normal conversion.  */
  71   inbuf = (const unsigned char *) s;
  72   status = DL_CALL_FCT (fcts->towc->__fct,
  73                         (fcts->towc, &data, &inbuf, inbuf + n,
  74                          NULL, &dummy, 0, 1));
  75
  76   /* There must not be any problems with the conversion but illegal input
  77      characters.  The output buffer must be large enough, otherwise the
  78      definition of MB_CUR_MAX is not correct.  All the other possible
  79      errors also must not happen.  */
  80   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  81           || status == __GCONV_ILLEGAL_INPUT
  82           || status == __GCONV_INCOMPLETE_INPUT
  83           || status == __GCONV_FULL_OUTPUT);
  84
  85   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  86       || status == __GCONV_FULL_OUTPUT)
  87     {
  88       if (data.__outbuf != (unsigned char *) outbuf
  89           && *(wchar_t *) outbuf == L'\0')
  90         {
  91           /* The converted character is the NUL character.  */
  92           assert (__mbsinit (data.__statep));
  93           result = 0;
  94         }
  95       else
  96         result = inbuf - (const unsigned char *) s;
  97     }
  98   else if (status == __GCONV_INCOMPLETE_INPUT)
  99     result = (size_t) -2;
 100   else
 101     {
 102       result = (size_t) -1;
 103       __set_errno (EILSEQ);
 104     }
 105
 106   return result;
 107 }
 108 libc_hidden_def (__mbrtowc)
 109 weak_alias (__mbrtowc, mbrtowc)
 110 libc_hidden_weak (mbrtowc)