wcsmbs/wcrtomb.c

   1 /* Copyright (C) 1996-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <assert.h>
  19 #include <dlfcn.h>
  20 #include <errno.h>
  21 #include <gconv.h>
  22 #include <stdlib.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26 #include <sysdep.h>
  27
  28 #ifndef EILSEQ
  29 # define EILSEQ EINVAL
  30 #endif
  31
  32
  33 /* This is the private state used if PS is NULL.  */
  34 static mbstate_t state;
  35
  36 size_t
  37 __wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
  38 {
  39   char buf[MB_LEN_MAX];
  40   struct __gconv_step_data data;
  41   int status;
  42   size_t result;
  43   size_t dummy;
  44   const struct gconv_fcts *fcts;
  45
  46   /* Set information for this step.  */
  47   data.__invocation_counter = 0;
  48   data.__internal_use = 1;
  49   data.__flags = __GCONV_IS_LAST;
  50   data.__statep = ps ?: &state;
  51
  52   /* A first special case is if S is NULL.  This means put PS in the
  53      initial state.  */
  54   if (s == NULL)
  55     {
  56       s = buf;
  57       wc = L'\0';
  58     }
  59
  60   /* Tell where we want to have the result.  */
  61   data.__outbuf = (unsigned char *) s;
  62   data.__outbufend = (unsigned char *) s + MB_CUR_MAX;
  63
  64   /* Get the conversion functions.  */
  65   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  66   __gconv_fct fct = fcts->tomb->__fct;
  67 #ifdef PTR_DEMANGLE
  68   if (fcts->tomb->__shlib_handle != NULL)
  69     PTR_DEMANGLE (fct);
  70 #endif
  71
  72   /* If WC is the NUL character we write into the output buffer the byte
  73      sequence necessary for PS to get into the initial state, followed
  74      by a NUL byte.  */
  75   if (wc == L'\0')
  76     {
  77       status = DL_CALL_FCT (fct, (fcts->tomb, &data, NULL, NULL,
  78                                   NULL, &dummy, 1, 1));
  79
  80       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  81         *data.__outbuf++ = '\0';
  82     }
  83   else
  84     {
  85       /* Do a normal conversion.  */
  86       const unsigned char *inbuf = (const unsigned char *) &wc;
  87
  88       status = DL_CALL_FCT (fct,
  89                             (fcts->tomb, &data, &inbuf,
  90                              inbuf + sizeof (wchar_t), NULL, &dummy, 0, 1));
  91     }
  92
  93   /* There must not be any problems with the conversion but illegal input
  94      characters.  The output buffer must be large enough, otherwise the
  95      definition of MB_CUR_MAX is not correct.  All the other possible
  96      errors also must not happen.  */
  97   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
  98           || status == __GCONV_ILLEGAL_INPUT
  99           || status == __GCONV_INCOMPLETE_INPUT
 100           || status == __GCONV_FULL_OUTPUT);
 101
 102   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 103       || status == __GCONV_FULL_OUTPUT)
 104     result = data.__outbuf - (unsigned char *) s;
 105   else
 106     {
 107       result = (size_t) -1;
 108       __set_errno (EILSEQ);
 109     }
 110
 111   return result;
 112 }
 113 weak_alias (__wcrtomb, wcrtomb)
 114 libc_hidden_weak (wcrtomb)