wcsmbs/mbrtowc.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2000, 2002, 2004, 2005
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <assert.h>
  22 #include <dlfcn.h>
  23 #include <errno.h>
  24 #include <gconv.h>
  25 #include <wchar.h>
  26 #include <wcsmbsload.h>
  27
  28 #include <sysdep.h>
  29
  30 #ifndef EILSEQ
  31 # define EILSEQ EINVAL
  32 #endif
  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, *endbuf;
  46   unsigned char *outbuf = (unsigned char *) (pwc ?: buf);
  47   const struct gconv_fcts *fcts;
  48
  49   /* Set information for this step.  */
  50   data.__invocation_counter = 0;
  51   data.__internal_use = 1;
  52   data.__flags = __GCONV_IS_LAST;
  53   data.__statep = ps ?: &state;
  54   data.__trans = NULL;
  55
  56   /* A first special case is if S is NULL.  This means put PS in the
  57      initial state.  */
  58   if (s == NULL)
  59     {
  60       outbuf = (unsigned char *) buf;
  61       s = "";
  62       n = 1;
  63     }
  64
  65   /* Tell where we want the result.  */
  66   data.__outbuf = outbuf;
  67   data.__outbufend = outbuf + sizeof (wchar_t);
  68
  69   /* Get the conversion functions.  */
  70   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  71
  72   /* Do a normal conversion.  */
  73   inbuf = (const unsigned char *) s;
  74   endbuf = inbuf + n;
  75   if (__builtin_expect (endbuf < inbuf, 0))
  76     endbuf = (const unsigned char *) ~(uintptr_t) 0;
  77   __gconv_fct fct = fcts->towc->__fct;
  78 #ifdef PTR_DEMANGLE
  79   if (fcts->towc->__shlib_handle != NULL)
  80     PTR_DEMANGLE (fct);
  81 #endif
  82   status = DL_CALL_FCT (fct, (fcts->towc, &data, &inbuf, endbuf,
  83                               NULL, &dummy, 0, 1));
  84
  85   /* There must not be any problems with the conversion but illegal input
  86      characters.  The output buffer must be large enough, otherwise the
  87      definition of MB_CUR_MAX is not correct.  All the other possible
  88      errors also must not happen.  */
  89   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  90           || status == __GCONV_ILLEGAL_INPUT
  91           || status == __GCONV_INCOMPLETE_INPUT
  92           || status == __GCONV_FULL_OUTPUT);
  93
  94   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  95       || status == __GCONV_FULL_OUTPUT)
  96     {
  97       if (data.__outbuf != (unsigned char *) outbuf
  98           && *(wchar_t *) outbuf == L'\0')
  99         {
 100           /* The converted character is the NUL character.  */
 101           assert (__mbsinit (data.__statep));
 102           result = 0;
 103         }
 104       else
 105         result = inbuf - (const unsigned char *) s;
 106     }
 107   else if (status == __GCONV_INCOMPLETE_INPUT)
 108     result = (size_t) -2;
 109   else
 110     {
 111       result = (size_t) -1;
 112       __set_errno (EILSEQ);
 113     }
 114
 115   return result;
 116 }
 117 libc_hidden_def (__mbrtowc)
 118 weak_alias (__mbrtowc, mbrtowc)
 119 libc_hidden_weak (mbrtowc)