wcsmbs/wcrtomb.c

   1 /* Copyright (C) 1996-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <dlfcn.h>
  21 #include <errno.h>
  22 #include <gconv.h>
  23 #include <stdlib.h>
  24 #include <wchar.h>
  25 #include <wcsmbsload.h>
  26
  27 #include <sysdep.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 size_t
  38 __wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
  39 {
  40   char buf[MB_LEN_MAX];
  41   struct __gconv_step_data data;
  42   int status;
  43   size_t result;
  44   size_t dummy;
  45   const struct gconv_fcts *fcts;
  46
  47   /* Set information for this step.  */
  48   data.__invocation_counter = 0;
  49   data.__internal_use = 1;
  50   data.__flags = __GCONV_IS_LAST;
  51   data.__statep = ps ?: &state;
  52
  53   /* A first special case is if S is NULL.  This means put PS in the
  54      initial state.  */
  55   if (s == NULL)
  56     {
  57       s = buf;
  58       wc = L'\0';
  59     }
  60
  61   /* Tell where we want to have the result.  */
  62   data.__outbuf = (unsigned char *) s;
  63   data.__outbufend = (unsigned char *) s + MB_CUR_MAX;
  64
  65   /* Get the conversion functions.  */
  66   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  67   __gconv_fct fct = fcts->tomb->__fct;
  68 #ifdef PTR_DEMANGLE
  69   if (fcts->tomb->__shlib_handle != NULL)
  70     PTR_DEMANGLE (fct);
  71 #endif
  72
  73   /* If WC is the NUL character we write into the output buffer the byte
  74      sequence necessary for PS to get into the initial state, followed
  75      by a NUL byte.  */
  76   if (wc == L'\0')
  77     {
  78       status = DL_CALL_FCT (fct, (fcts->tomb, &data, NULL, NULL,
  79                                   NULL, &dummy, 1, 1));
  80
  81       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  82         *data.__outbuf++ = '\0';
  83     }
  84   else
  85     {
  86       /* Do a normal conversion.  */
  87       const unsigned char *inbuf = (const unsigned char *) &wc;
  88
  89       status = DL_CALL_FCT (fct,
  90                             (fcts->tomb, &data, &inbuf,
  91                              inbuf + sizeof (wchar_t), NULL, &dummy, 0, 1));
  92     }
  93
  94   /* There must not be any problems with the conversion but illegal input
  95      characters.  The output buffer must be large enough, otherwise the
  96      definition of MB_CUR_MAX is not correct.  All the other possible
  97      errors also must not happen.  */
  98   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  99           || status == __GCONV_ILLEGAL_INPUT
 100           || status == __GCONV_INCOMPLETE_INPUT
 101           || status == __GCONV_FULL_OUTPUT);
 102
 103   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 104       || status == __GCONV_FULL_OUTPUT)
 105     result = data.__outbuf - (unsigned char *) s;
 106   else
 107     {
 108       result = (size_t) -1;
 109       __set_errno (EILSEQ);
 110     }
 111
 112   return result;
 113 }
 114 weak_alias (__wcrtomb, wcrtomb)
 115 libc_hidden_weak (wcrtomb)
 116
 117 /* There should be no difference between the UTF-32 handling required
 118    by c32rtomb and the wchar_t handling which has long since been
 119    implemented in wcrtomb.  */
 120 weak_alias (__wcrtomb, c32rtomb)