wcsmbs/wcrtomb.c

   1 /* Copyright (C) 1996-2022 Free Software Foundation, Inc.
   2    Copyright The GNU Toolchain Authors.
   3    This file is part of the GNU C Library.
   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    <https://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 <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 size_t
  39 __wcrtomb_internal (char *s, wchar_t wc, mbstate_t *ps, size_t s_size)
  40 {
  41   char buf[MB_LEN_MAX];
  42   struct __gconv_step_data data;
  43   int status;
  44   size_t result;
  45   size_t dummy;
  46   const struct gconv_fcts *fcts;
  47
  48   /* Set information for this step.  */
  49   data.__invocation_counter = 0;
  50   data.__internal_use = 1;
  51   data.__flags = __GCONV_IS_LAST;
  52   data.__statep = ps ?: &state;
  53
  54   /* A first special case is if S is NULL.  This means put PS in the
  55      initial state.  */
  56   if (s == NULL)
  57     wc = L'\0';
  58
  59   /* Tell where we want to have the result.  */
  60   data.__outbuf = (unsigned char *) buf;
  61   data.__outbufend = (unsigned char *) buf + sizeof buf;
  62
  63   /* Get the conversion functions.  */
  64   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  65   __gconv_fct fct = fcts->tomb->__fct;
  66 #ifdef PTR_DEMANGLE
  67   if (fcts->tomb->__shlib_handle != NULL)
  68     PTR_DEMANGLE (fct);
  69 #endif
  70
  71   /* If WC is the NUL character we write into the output buffer the byte
  72      sequence necessary for PS to get into the initial state, followed
  73      by a NUL byte.  */
  74   if (wc == L'\0')
  75     {
  76       status = DL_CALL_FCT (fct, (fcts->tomb, &data, NULL, NULL,
  77                                   NULL, &dummy, 1, 1));
  78
  79       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  80         *data.__outbuf++ = '\0';
  81     }
  82   else
  83     {
  84       /* Do a normal conversion.  */
  85       const unsigned char *inbuf = (const unsigned char *) &wc;
  86
  87       status = DL_CALL_FCT (fct,
  88                             (fcts->tomb, &data, &inbuf,
  89                              inbuf + sizeof (wchar_t), NULL, &dummy, 0, 1));
  90     }
  91
  92   /* There must not be any problems with the conversion but illegal input
  93      characters.  The output buffer must be large enough, otherwise the
  94      definition of MB_CUR_MAX is not correct.  All the other possible
  95      errors also must not happen.  */
  96   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  97           || status == __GCONV_ILLEGAL_INPUT
  98           || status == __GCONV_INCOMPLETE_INPUT
  99           || status == __GCONV_FULL_OUTPUT);
 100
 101   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 102       || status == __GCONV_FULL_OUTPUT)
 103     {
 104       result = data.__outbuf - (unsigned char *) buf;
 105
 106       if (s != NULL)
 107         {
 108           if (result > s_size)
 109             __chk_fail ();
 110
 111           memcpy (s, buf, result);
 112         }
 113     }
 114   else
 115     {
 116       result = (size_t) -1;
 117       __set_errno (EILSEQ);
 118     }
 119
 120   return result;
 121 }
 122
 123 size_t
 124 __wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
 125 {
 126   return __wcrtomb_internal (s, wc, ps, (size_t) -1);
 127 }
 128 weak_alias (__wcrtomb, wcrtomb)
 129 libc_hidden_weak (wcrtomb)