wcsmbs/mbsrtowcs_l.c

   1 /* Copyright (C) 2002-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.org>, 2002.
   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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <ctype.h>
  21 #include <string.h>
  22 #include "wcsmbsload.h"
  23 #include <dlfcn.h>
  24 #include <errno.h>
  25 #include <gconv.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <wchar.h>
  29 #include <wcsmbsload.h>
  30
  31 #include <sysdep.h>
  32
  33 #ifndef EILSEQ
  34 # define EILSEQ EINVAL
  35 #endif
  36
  37
  38 size_t
  39 attribute_hidden
  40 __mbsrtowcs_l (wchar_t *dst, const char **src, size_t len, mbstate_t *ps,
  41                __locale_t l)
  42 {
  43   struct __gconv_step_data data;
  44   size_t result;
  45   int status;
  46   struct __gconv_step *towc;
  47   size_t non_reversible;
  48   const struct gconv_fcts *fcts;
  49
  50   /* Tell where we want the result.  */
  51   data.__invocation_counter = 0;
  52   data.__internal_use = 1;
  53   data.__flags = __GCONV_IS_LAST;
  54   data.__statep = ps;
  55
  56   /* Get the conversion functions.  */
  57   fcts = get_gconv_fcts (l->__locales[LC_CTYPE]);
  58
  59   /* Get the structure with the function pointers.  */
  60   towc = fcts->towc;
  61   __gconv_fct fct = towc->__fct;
  62 #ifdef PTR_DEMANGLE
  63   if (towc->__shlib_handle != NULL)
  64     PTR_DEMANGLE (fct);
  65 #endif
  66
  67   /* We have to handle DST == NULL special.  */
  68   if (dst == NULL)
  69     {
  70       mbstate_t temp_state;
  71       wchar_t buf[64];          /* Just an arbitrary size.  */
  72       const unsigned char *inbuf = (const unsigned char *) *src;
  73       const unsigned char *srcend = inbuf + strlen (*src) + 1;
  74
  75       temp_state = *data.__statep;
  76       data.__statep = &temp_state;
  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 (fct, (towc, &data, &inbuf, srcend, NULL,
  85                                       &non_reversible, 0, 1));
  86
  87           result += (wchar_t *) data.__outbuf - buf;
  88         }
  89       while (status == __GCONV_FULL_OUTPUT);
  90
  91       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  92         {
  93           /* There better should be a NUL wide char at the end.  */
  94           assert (((wchar_t *) data.__outbuf)[-1] == L'\0');
  95           /* Don't count the NUL character in.  */
  96           --result;
  97         }
  98     }
  99   else
 100     {
 101       /* This code is based on the safe assumption that all internal
 102          multi-byte encodings use the NUL byte only to mark the end
 103          of the string.  */
 104       const unsigned char *srcp = (const unsigned char *) *src;
 105       const unsigned char *srcend;
 106
 107       data.__outbuf = (unsigned char *) dst;
 108       data.__outbufend = data.__outbuf + len * sizeof (wchar_t);
 109
 110       status = __GCONV_FULL_OUTPUT;
 111
 112       while (len > 0)
 113         {
 114           /* Pessimistic guess as to how much input we can use.  In the
 115              worst case we need one input byte for one output wchar_t.  */
 116           srcend = srcp + __strnlen ((const char *) srcp, len) + 1;
 117
 118           status = DL_CALL_FCT (fct, (towc, &data, &srcp, srcend, NULL,
 119                                       &non_reversible, 0, 1));
 120           if ((status != __GCONV_EMPTY_INPUT
 121                && status != __GCONV_INCOMPLETE_INPUT)
 122               /* Not all input read.  */
 123               || srcp != srcend
 124               /* Reached the end of the input.  */
 125               || srcend[-1] == '\0')
 126             break;
 127
 128           len = (wchar_t *) data.__outbufend - (wchar_t *) data.__outbuf;
 129         }
 130
 131       /* Make the end if the input known to the caller.  */
 132       *src = (const char *) srcp;
 133
 134       result = (wchar_t *) data.__outbuf - dst;
 135
 136       /* We have to determine whether the last character converted
 137          is the NUL character.  */
 138       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 139           && ((wchar_t *) dst)[result - 1] == L'\0')
 140         {
 141           assert (result > 0);
 142           assert (__mbsinit (data.__statep));
 143           *src = NULL;
 144           --result;
 145         }
 146     }
 147
 148   /* There must not be any problems with the conversion but illegal input
 149      characters.  */
 150   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 151           || status == __GCONV_ILLEGAL_INPUT
 152           || status == __GCONV_INCOMPLETE_INPUT
 153           || status == __GCONV_FULL_OUTPUT);
 154
 155   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 156       && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)
 157     {
 158       result = (size_t) -1;
 159       __set_errno (EILSEQ);
 160     }
 161
 162   return result;
 163 }