wcsmbs/mbsnrtowcs.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2000 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 <string.h>
  24 #include <wchar.h>
  25 #include <wcsmbsload.h>
  26
  27 #include <assert.h>
  28
  29 #ifndef EILSEQ
  30 # define EILSEQ EINVAL
  31 #endif
  32
  33
  34 /* This is the private state used if PS is NULL.  */
  35 static mbstate_t state;
  36
  37 /* This is a non-standard function but it is very useful in the
  38    implementation of stdio because we have to deal with unterminated
  39    buffers.  At most NMC bytes will be converted.  */
  40 size_t
  41 __mbsnrtowcs (dst, src, nmc, len, ps)
  42      wchar_t *dst;
  43      const char **src;
  44      size_t nmc;
  45      size_t len;
  46      mbstate_t *ps;
  47 {
  48   const unsigned char *srcend;
  49   struct __gconv_step_data data;
  50   size_t result;
  51   int status;
  52   struct __gconv_step *towc;
  53   size_t dummy;
  54
  55   /* Tell where we want the result.  */
  56   data.__invocation_counter = 0;
  57   data.__internal_use = 1;
  58   data.__flags = __GCONV_IS_LAST;
  59   data.__statep = ps ?: &state;
  60   data.__trans = NULL;
  61
  62   if (nmc == 0)
  63     return 0;
  64   srcend = *src + __strnlen (*src, nmc - 1) + 1;
  65
  66   /* Make sure we use the correct function.  */
  67   update_conversion_ptrs ();
  68
  69   /* Get the structure with the function pointers.  */
  70   towc = __wcsmbs_gconv_fcts.towc;
  71
  72   /* We have to handle DST == NULL special.  */
  73   if (dst == NULL)
  74     {
  75       wchar_t buf[64];          /* Just an arbitrary size.  */
  76       const unsigned char *inbuf = *src;
  77
  78       result = 0;
  79       data.__outbufend = (unsigned char *) buf + sizeof (buf);
  80       do
  81         {
  82           data.__outbuf = (unsigned char *) buf;
  83
  84           status = DL_CALL_FCT (towc->__fct,
  85                                 (towc, &data, &inbuf, srcend, NULL,
  86                                  &dummy, 0, 1));
  87
  88           result += (wchar_t *) data.__outbuf - buf;
  89         }
  90       while (status == __GCONV_FULL_OUTPUT);
  91
  92       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  93           && ((wchar_t *) data.__outbuf)[-1] == L'\0')
  94         /* Don't count the NUL character in.  */
  95         --result;
  96     }
  97   else
  98     {
  99       /* This code is based on the safe assumption that all internal
 100          multi-byte encodings use the NUL byte only to mark the end
 101          of the string.  */
 102       data.__outbuf = (unsigned char *) dst;
 103       data.__outbufend = data.__outbuf + len * sizeof (wchar_t);
 104
 105       status = DL_CALL_FCT (towc->__fct,
 106                             (towc, &data, (const unsigned char **) src, srcend,
 107                              NULL, &dummy, 0, 1));
 108
 109       result = (wchar_t *) data.__outbuf - dst;
 110
 111       /* We have to determine whether the last character converted
 112          is the NUL character.  */
 113       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 114           && (assert (result > 0),
 115               ((wchar_t *) dst)[result - 1] == L'\0'))
 116         {
 117           assert (__mbsinit (data.__statep));
 118           *src = NULL;
 119           --result;
 120         }
 121     }
 122
 123   /* There must not be any problems with the conversion but illegal input
 124      characters.  */
 125   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 126           || status == __GCONV_ILLEGAL_INPUT
 127           || status == __GCONV_INCOMPLETE_INPUT
 128           || status == __GCONV_FULL_OUTPUT);
 129
 130   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 131       && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)
 132     {
 133       result = (size_t) -1;
 134       __set_errno (EILSEQ);
 135     }
 136
 137   return result;
 138 }
 139 weak_alias (__mbsnrtowcs, mbsnrtowcs)