1/* Copyright (C) 1995,1997,1999,2000,2001,2002 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, write to the Free
16   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17   02111-1307 USA.
18
19   As a special exception, if you link the code in this file with
20   files compiled with a GNU compiler to produce an executable,
21   that does not cause the resulting executable to be covered by
22   the GNU Lesser General Public License.  This exception does not
23   however invalidate any other reasons why the executable file
24   might be covered by the GNU Lesser General Public License.
25   This exception applies to code released by its copyright holders
26   in files containing the exception.  */
27
28#include <malloc.h>
29#include <string.h>
30#include "libioP.h"
31#include "stdio.h"
32#include <stdio_ext.h>
33#include "strfile.h"
34
35int
36_IO_vasprintf (result_ptr, format, args)
37     char **result_ptr;
38     const char *format;
39     _IO_va_list args;
40{
41  /* Initial size of the buffer to be used.  Will be doubled each time an
42     overflow occurs.  */
43  const _IO_size_t init_string_size = 100;
44  char *string;
45  _IO_strfile sf;
46  int ret;
47  _IO_size_t needed;
48  _IO_size_t allocated;
49  string = (char *) malloc (init_string_size);
50  if (string == NULL)
51    return -1;
52#ifdef _IO_MTSAFE_IO
53  sf._sbf._f._lock = NULL;
54#endif
55  _IO_no_init ((_IO_FILE *) &sf._sbf, _IO_USER_LOCK, -1, NULL, NULL);
56  _IO_JUMPS ((struct _IO_FILE_plus *) &sf._sbf) = &_IO_str_jumps;
57  INTUSE(_IO_str_init_static) (&sf, string, init_string_size, string);
58  sf._sbf._f._flags &= ~_IO_USER_BUF;
59  sf._s._allocate_buffer = (_IO_alloc_type) malloc;
60  sf._s._free_buffer = (_IO_free_type) free;
61  ret = INTUSE(_IO_vfprintf) (&sf._sbf._f, format, args);
62  if (ret < 0)
63    {
64      free (sf._sbf._f._IO_buf_base);
65      return ret;
66    }
67  /* Only use realloc if the size we need is of the same order of
68     magnitude then the memory we allocated.  */
69  needed = sf._sbf._f._IO_write_ptr - sf._sbf._f._IO_write_base + 1;
70  allocated = sf._sbf._f._IO_write_end - sf._sbf._f._IO_write_base;
71  if ((allocated << 1) <= needed)
72    *result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed);
73  else
74    {
75      *result_ptr = (char *) malloc (needed);
76      if (*result_ptr != NULL)
77	{
78	  memcpy (*result_ptr, sf._sbf._f._IO_buf_base, needed - 1);
79	  free (sf._sbf._f._IO_buf_base);
80	}
81      else
82	/* We have no choice, use the buffer we already have.  */
83	*result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed);
84    }
85  if (*result_ptr == NULL)
86    *result_ptr = sf._sbf._f._IO_buf_base;
87  (*result_ptr)[needed - 1] = '\0';
88  return ret;
89}
90
91#ifdef weak_alias
92weak_alias (_IO_vasprintf, vasprintf)
93#endif
94