libio/vswprintf.c

   1 /* Copyright (C) 1994, 1997, 1999-2002, 2004, 2005, 2006
   2    Free Software Foundation, Inc.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.
  19
  20    As a special exception, if you link the code in this file with
  21    files compiled with a GNU compiler to produce an executable,
  22    that does not cause the resulting executable to be covered by
  23    the GNU Lesser General Public License.  This exception does not
  24    however invalidate any other reasons why the executable file
  25    might be covered by the GNU Lesser General Public License.
  26    This exception applies to code released by its copyright holders
  27    in files containing the exception.  */
  28
  29 #include "libioP.h"
  30 #include "strfile.h"
  31
  32
  33 static wint_t _IO_wstrn_overflow (_IO_FILE *fp, wint_t c) __THROW;
  34
  35 static wint_t
  36 _IO_wstrn_overflow (fp, c)
  37      _IO_FILE *fp;
  38      wint_t c;
  39 {
  40   /* When we come to here this means the user supplied buffer is
  41      filled.  But since we must return the number of characters which
  42      would have been written in total we must provide a buffer for
  43      further use.  We can do this by writing on and on in the overflow
  44      buffer in the _IO_wstrnfile structure.  */
  45   _IO_wstrnfile *snf = (_IO_wstrnfile *) fp;
  46
  47   if (fp->_wide_data->_IO_buf_base != snf->overflow_buf)
  48     {
  49       INTUSE(_IO_wsetb) (fp, snf->overflow_buf,
  50                          snf->overflow_buf + (sizeof (snf->overflow_buf)
  51                                               / sizeof (wchar_t)), 0);
  52
  53       fp->_wide_data->_IO_write_base = snf->overflow_buf;
  54       fp->_wide_data->_IO_read_base = snf->overflow_buf;
  55       fp->_wide_data->_IO_read_ptr = snf->overflow_buf;
  56       fp->_wide_data->_IO_read_end = (snf->overflow_buf
  57                                       + (sizeof (snf->overflow_buf)
  58                                          / sizeof (wchar_t)));
  59     }
  60
  61   fp->_wide_data->_IO_write_ptr = snf->overflow_buf;
  62   fp->_wide_data->_IO_write_end = snf->overflow_buf;
  63
  64   /* Since we are not really interested in storing the characters
  65      which do not fit in the buffer we simply ignore it.  */
  66   return c;
  67 }
  68
  69
  70 const struct _IO_jump_t _IO_wstrn_jumps attribute_hidden =
  71 {
  72   JUMP_INIT_DUMMY,
  73   JUMP_INIT(finish, _IO_wstr_finish),
  74   JUMP_INIT(overflow, (_IO_overflow_t) _IO_wstrn_overflow),
  75   JUMP_INIT(underflow, (_IO_underflow_t) _IO_wstr_underflow),
  76   JUMP_INIT(uflow, (_IO_underflow_t) INTUSE(_IO_wdefault_uflow)),
  77   JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
  78   JUMP_INIT(xsputn, INTUSE(_IO_wdefault_xsputn)),
  79   JUMP_INIT(xsgetn, INTUSE(_IO_wdefault_xsgetn)),
  80   JUMP_INIT(seekoff, _IO_wstr_seekoff),
  81   JUMP_INIT(seekpos, _IO_default_seekpos),
  82   JUMP_INIT(setbuf, _IO_default_setbuf),
  83   JUMP_INIT(sync, _IO_default_sync),
  84   JUMP_INIT(doallocate, INTUSE(_IO_wdefault_doallocate)),
  85   JUMP_INIT(read, _IO_default_read),
  86   JUMP_INIT(write, _IO_default_write),
  87   JUMP_INIT(seek, _IO_default_seek),
  88   JUMP_INIT(close, _IO_default_close),
  89   JUMP_INIT(stat, _IO_default_stat),
  90   JUMP_INIT(showmanyc, _IO_default_showmanyc),
  91   JUMP_INIT(imbue, _IO_default_imbue)
  92 };
  93
  94
  95 int
  96 _IO_vswprintf (string, maxlen, format, args)
  97      wchar_t *string;
  98      _IO_size_t maxlen;
  99      const wchar_t *format;
 100      _IO_va_list args;
 101 {
 102   _IO_wstrnfile sf;
 103   int ret;
 104   struct _IO_wide_data wd;
 105 #ifdef _IO_MTSAFE_IO
 106   sf.f._sbf._f._lock = NULL;
 107 #endif
 108
 109   if (maxlen == 0)
 110     /* Since we have to write at least the terminating L'\0' a buffer
 111        length of zero always makes the function fail.  */
 112     return -1;
 113
 114   _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, 0, &wd, &_IO_wstrn_jumps);
 115   _IO_fwide (&sf.f._sbf._f, 1);
 116   string[0] = L'\0';
 117   _IO_wstr_init_static (&sf.f._sbf._f, string, maxlen - 1, string);
 118   ret = _IO_vfwprintf ((_IO_FILE *) &sf.f._sbf, format, args);
 119
 120   if (sf.f._sbf._f._wide_data->_IO_buf_base == sf.overflow_buf)
 121     /* ISO C99 requires swprintf/vswprintf to return an error if the
 122        output does not fit in the provided buffer.  */
 123     return -1;
 124
 125   /* Terminate the string.  */
 126   *sf.f._sbf._f._wide_data->_IO_write_ptr = '\0';
 127
 128   return ret;
 129 }
 130 weak_alias (_IO_vswprintf, __vswprintf)
 131 ldbl_weak_alias (_IO_vswprintf, vswprintf)