wcsmbs/mbrtoc16.c

   1 /* Copyright (C) 2011-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
   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 <uchar.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 mbrtoc16 (char16_t *pc16, const char *s, size_t n, mbstate_t *ps)
  38 {
  39   if (ps == NULL)
  40     ps = &state;
  41
  42   /* The standard text does not say that S being NULL means the state
  43      is reset even if the second half of a surrogate still have to be
  44      returned.  In fact, the error code description indicates
  45      otherwise.  Therefore always first try to return a second
  46      half.  */
  47   if (ps->__count & 0x80000000)
  48     {
  49       /* We have to return the second word for a surrogate.  */
  50       ps->__count &= 0x7fffffff;
  51       *pc16 = ps->__value.__wch;
  52       ps->__value.__wch = L'\0';
  53       return (size_t) -3;
  54     }
  55
  56   wchar_t wc;
  57   struct __gconv_step_data data;
  58   int status;
  59   size_t result;
  60   size_t dummy;
  61   const unsigned char *inbuf, *endbuf;
  62   unsigned char *outbuf = (unsigned char *) &wc;
  63   const struct gconv_fcts *fcts;
  64
  65   /* Set information for this step.  */
  66   data.__invocation_counter = 0;
  67   data.__internal_use = 1;
  68   data.__flags = __GCONV_IS_LAST;
  69   data.__statep = ps;
  70
  71   /* A first special case is if S is NULL.  This means put PS in the
  72      initial state.  */
  73   if (s == NULL)
  74     {
  75       pc16 = NULL;
  76       s = "";
  77       n = 1;
  78     }
  79
  80   if (n == 0)
  81     return (size_t) -2;
  82
  83   /* Tell where we want the result.  */
  84   data.__outbuf = outbuf;
  85   data.__outbufend = outbuf + sizeof (wchar_t);
  86
  87   /* Get the conversion functions.  */
  88   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  89
  90   /* Do a normal conversion.  */
  91   inbuf = (const unsigned char *) s;
  92   endbuf = inbuf + n;
  93   if (__glibc_unlikely (endbuf < inbuf))
  94     {
  95       endbuf = (const unsigned char *) ~(uintptr_t) 0;
  96       if (endbuf == inbuf)
  97         goto ilseq;
  98     }
  99   __gconv_fct fct = fcts->towc->__fct;
 100 #ifdef PTR_DEMANGLE
 101   if (fcts->towc->__shlib_handle != NULL)
 102     PTR_DEMANGLE (fct);
 103 #endif
 104
 105   status = DL_CALL_FCT (fct, (fcts->towc, &data, &inbuf, endbuf,
 106                               NULL, &dummy, 0, 1));
 107
 108   /* There must not be any problems with the conversion but illegal input
 109      characters.  The output buffer must be large enough, otherwise the
 110      definition of MB_CUR_MAX is not correct.  All the other possible
 111      errors also must not happen.  */
 112   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 113           || status == __GCONV_ILLEGAL_INPUT
 114           || status == __GCONV_INCOMPLETE_INPUT
 115           || status == __GCONV_FULL_OUTPUT);
 116
 117   if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 118       || status == __GCONV_FULL_OUTPUT)
 119     {
 120       result = inbuf - (const unsigned char *) s;
 121
 122       if (wc < 0x10000)
 123         {
 124           if (pc16 != NULL)
 125             *pc16 = wc;
 126
 127           if (data.__outbuf != outbuf && wc == L'\0')
 128             {
 129               /* The converted character is the NUL character.  */
 130               assert (__mbsinit (data.__statep));
 131               result = 0;
 132             }
 133         }
 134       else
 135         {
 136           /* This is a surrogate.  */
 137           if (pc16 != NULL)
 138             *pc16 = 0xd7c0 + (wc >> 10);
 139
 140           ps->__count |= 0x80000000;
 141           ps->__value.__wch = 0xdc00 + (wc & 0x3ff);
 142         }
 143     }
 144   else if (status == __GCONV_INCOMPLETE_INPUT)
 145     result = (size_t) -2;
 146   else
 147     {
 148     ilseq:
 149       result = (size_t) -1;
 150       __set_errno (EILSEQ);
 151     }
 152
 153   return result;
 154 }