wcsmbs/mbsnrtowcs.c

   1 /* Copyright (C) 1996-2000, 2002, 2005, 2008 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       mbstate_t temp_state;
  83       wchar_t buf[64];          /* Just an arbitrary size.  */
  84       const unsigned char *inbuf = (const unsigned char *) *src;
  85
  86       temp_state = *data.__statep;
  87       data.__statep = &temp_state;
  88
  89       result = 0;
  90       data.__outbufend = (unsigned char *) buf + sizeof (buf);
  91       do
  92         {
  93           data.__outbuf = (unsigned char *) buf;
  94
  95           status = DL_CALL_FCT (fct, (towc, &data, &inbuf, srcend, NULL,
  96                                       &dummy, 0, 1));
  97
  98           result += (wchar_t *) data.__outbuf - buf;
  99         }
 100       while (status == __GCONV_FULL_OUTPUT);
 101
 102       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 103           && ((wchar_t *) data.__outbuf)[-1] == L'\0')
 104         /* Don't count the NUL character in.  */
 105         --result;
 106     }
 107   else
 108     {
 109       /* This code is based on the safe assumption that all internal
 110          multi-byte encodings use the NUL byte only to mark the end
 111          of the string.  */
 112       data.__outbuf = (unsigned char *) dst;
 113       data.__outbufend = data.__outbuf + len * sizeof (wchar_t);
 114
 115       status = DL_CALL_FCT (fct,
 116                             (towc, &data, (const unsigned char **) src, srcend,
 117                              NULL, &dummy, 0, 1));
 118
 119       result = (wchar_t *) data.__outbuf - dst;
 120
 121       /* We have to determine whether the last character converted
 122          is the NUL character.  */
 123       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 124           && (assert (result > 0),
 125               ((wchar_t *) dst)[result - 1] == L'\0'))
 126         {
 127           assert (__mbsinit (data.__statep));
 128           *src = NULL;
 129           --result;
 130         }
 131     }
 132
 133   /* There must not be any problems with the conversion but illegal input
 134      characters.  */
 135   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 136           || status == __GCONV_ILLEGAL_INPUT
 137           || status == __GCONV_INCOMPLETE_INPUT
 138           || status == __GCONV_FULL_OUTPUT);
 139
 140   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 141       && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)
 142     {
 143       result = (size_t) -1;
 144       __set_errno (EILSEQ);
 145     }
 146
 147   return result;
 148 }
 149 weak_alias (__mbsnrtowcs, mbsnrtowcs)