wcsmbs/mbsnrtowcs.c

   1 /* Copyright (C) 1996-2000, 2002, 2005 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 <assert.h>
  21 #include <dlfcn.h>
  22 #include <errno.h>
  23 #include <gconv.h>
  24 #include <string.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
  35 /* This is the private state used if PS is NULL.  */
  36 static mbstate_t state;
  37
  38 /* This is a non-standard function but it is very useful in the
  39    implementation of stdio because we have to deal with unterminated
  40    buffers.  At most NMC bytes will be converted.  */
  41 size_t
  42 __mbsnrtowcs (dst, src, nmc, len, ps)
  43      wchar_t *dst;
  44      const char **src;
  45      size_t nmc;
  46      size_t len;
  47      mbstate_t *ps;
  48 {
  49   const unsigned char *srcend;
  50   struct __gconv_step_data data;
  51   size_t result;
  52   int status;
  53   struct __gconv_step *towc;
  54   size_t dummy;
  55   const struct gconv_fcts *fcts;
  56
  57   /* Tell where we want the result.  */
  58   data.__invocation_counter = 0;
  59   data.__internal_use = 1;
  60   data.__flags = __GCONV_IS_LAST;
  61   data.__statep = ps ?: &state;
  62   data.__trans = NULL;
  63
  64   if (nmc == 0)
  65     return 0;
  66   srcend = (const unsigned char *) *src + __strnlen (*src, nmc - 1) + 1;
  67
  68   /* Get the conversion functions.  */
  69   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  70
  71   /* Get the structure with the function pointers.  */
  72   towc = fcts->towc;
  73   __gconv_fct fct = towc->__fct;
  74 #ifdef PTR_DEMANGLE
  75   if (towc->__shlib_handle != NULL)
  76     PTR_DEMANGLE (fct);
  77 #endif
  78
  79   /* We have to handle DST == NULL special.  */
  80   if (dst == NULL)
  81     {
  82       wchar_t buf[64];          /* Just an arbitrary size.  */
  83       const unsigned char *inbuf = (const unsigned char *) *src;
  84
  85       result = 0;
  86       data.__outbufend = (unsigned char *) buf + sizeof (buf);
  87       do
  88         {
  89           data.__outbuf = (unsigned char *) buf;
  90
  91           status = DL_CALL_FCT (fct, (towc, &data, &inbuf, srcend, NULL,
  92                                       &dummy, 0, 1));
  93
  94           result += (wchar_t *) data.__outbuf - buf;
  95         }
  96       while (status == __GCONV_FULL_OUTPUT);
  97
  98       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  99           && ((wchar_t *) data.__outbuf)[-1] == L'\0')
 100         /* Don't count the NUL character in.  */
 101         --result;
 102     }
 103   else
 104     {
 105       /* This code is based on the safe assumption that all internal
 106          multi-byte encodings use the NUL byte only to mark the end
 107          of the string.  */
 108       data.__outbuf = (unsigned char *) dst;
 109       data.__outbufend = data.__outbuf + len * sizeof (wchar_t);
 110
 111       status = DL_CALL_FCT (fct,
 112                             (towc, &data, (const unsigned char **) src, srcend,
 113                              NULL, &dummy, 0, 1));
 114
 115       result = (wchar_t *) data.__outbuf - dst;
 116
 117       /* We have to determine whether the last character converted
 118          is the NUL character.  */
 119       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 120           && (assert (result > 0),
 121               ((wchar_t *) dst)[result - 1] == L'\0'))
 122         {
 123           assert (__mbsinit (data.__statep));
 124           *src = NULL;
 125           --result;
 126         }
 127     }
 128
 129   /* There must not be any problems with the conversion but illegal input
 130      characters.  */
 131   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 132           || status == __GCONV_ILLEGAL_INPUT
 133           || status == __GCONV_INCOMPLETE_INPUT
 134           || status == __GCONV_FULL_OUTPUT);
 135
 136   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 137       && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)
 138     {
 139       result = (size_t) -1;
 140       __set_errno (EILSEQ);
 141     }
 142
 143   return result;
 144 }
 145 weak_alias (__mbsnrtowcs, mbsnrtowcs)