/* Copyright (C) 1995-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.

   As a special exception, if you link the code in this file with

   files compiled with a GNU compiler to produce an executable,

   that does not cause the resulting executable to be covered by

   the GNU Lesser General Public License.  This exception does not

   however invalidate any other reasons why the executable file

   might be covered by the GNU Lesser General Public License.

   This exception applies to code released by its copyright holders

   in files containing the exception.  */

#include <malloc.h>

#include <string.h>

#include <stdio.h>

#include <stdio_ext.h>

#include "../libio/libioP.h"

#include "../libio/strfile.h"

int

__vasprintf_chk (char **result_ptr, int flags, const char *format,

		 va_list args)

{

  /* Initial size of the buffer to be used.  Will be doubled each time an

     overflow occurs.  */

  const size_t init_string_size = 100;

  char *string;

  _IO_strfile sf;

  int ret;

  size_t needed;

  size_t allocated;

  /* No need to clear the memory here (unlike for open_memstream) since

     we know we will never seek on the stream.  */

  string = (char *) malloc (init_string_size);

  if (string == NULL)

    return -1;

#ifdef _IO_MTSAFE_IO

  sf._sbf._f._lock = NULL;

#endif

  _IO_no_init (&sf._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);

  _IO_JUMPS (&sf._sbf) = &_IO_str_jumps;

  _IO_str_init_static_internal (&sf, string, init_string_size, string);

  sf._sbf._f._flags &= ~_IO_USER_BUF;

  sf._s._allocate_buffer_unused = (_IO_alloc_type) malloc;

  sf._s._free_buffer_unused = (_IO_free_type) free;

  /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n

     can only come from read-only format strings.  */

  if (flags > 0)

    sf._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY;

  ret = _IO_vfprintf (&sf._sbf._f, format, args);

  if (ret < 0)

    {

      free (sf._sbf._f._IO_buf_base);

      return ret;

    }

  /* Only use realloc if the size we need is of the same (binary)

     order of magnitude then the memory we allocated.  */

  needed = sf._sbf._f._IO_write_ptr - sf._sbf._f._IO_write_base + 1;

  allocated = sf._sbf._f._IO_write_end - sf._sbf._f._IO_write_base;

  if ((allocated >> 1) <= needed)

    *result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed);

  else

    {

      *result_ptr = (char *) malloc (needed);

      if (*result_ptr != NULL)

	{

	  memcpy (*result_ptr, sf._sbf._f._IO_buf_base, needed - 1);

	  free (sf._sbf._f._IO_buf_base);

	}

      else

	/* We have no choice, use the buffer we already have.  */

	*result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed);

    }

  if (*result_ptr == NULL)

    *result_ptr = sf._sbf._f._IO_buf_base;

  (*result_ptr)[needed - 1] = '\0';

  return ret;

}

libc_hidden_def (__vasprintf_chk)