1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
| | /* Variable-sized buffer with on-stack default allocation.
Copyright (C) 2015-2021 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
<https://www.gnu.org/licenses/>. */
#ifndef _LIBC
# include <libc-config.h>
#endif
#include <scratch_buffer.h>
#include <errno.h>
#include <limits.h>
bool
__libc_scratch_buffer_set_array_size (struct scratch_buffer *buffer,
size_t nelem, size_t size)
{
size_t new_length = nelem * size;
/* Avoid overflow check if both values are small. */
if ((nelem | size) >> (sizeof (size_t) * CHAR_BIT / 2) != 0
&& nelem != 0 && size != new_length / nelem)
{
/* Overflow. Discard the old buffer, but it must remain valid
to free. */
scratch_buffer_free (buffer);
scratch_buffer_init (buffer);
__set_errno (ENOMEM);
return false;
}
if (new_length <= buffer->length)
return true;
/* Discard old buffer. */
scratch_buffer_free (buffer);
char *new_ptr = malloc (new_length);
if (new_ptr == NULL)
{
/* Buffer must remain valid to free. */
scratch_buffer_init (buffer);
return false;
}
/* Install new heap-based buffer. */
buffer->data = new_ptr;
buffer->length = new_length;
return true;
}
libc_hidden_def (__libc_scratch_buffer_set_array_size)
|