1 | /* Variable-sized buffer with on-stack default allocation. |
2 | Copyright (C) 2015-2017 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, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <scratch_buffer.h> |
20 | #include <errno.h> |
21 | |
22 | bool |
23 | __libc_scratch_buffer_grow (struct scratch_buffer *buffer) |
24 | { |
25 | void *new_ptr; |
26 | size_t new_length = buffer->length * 2; |
27 | |
28 | /* Discard old buffer. */ |
29 | scratch_buffer_free (buffer); |
30 | |
31 | /* Check for overflow. */ |
32 | if (__glibc_likely (new_length >= buffer->length)) |
33 | new_ptr = malloc (new_length); |
34 | else |
35 | { |
36 | __set_errno (ENOMEM); |
37 | new_ptr = NULL; |
38 | } |
39 | |
40 | if (__glibc_unlikely (new_ptr == NULL)) |
41 | { |
42 | /* Buffer must remain valid to free. */ |
43 | scratch_buffer_init (buffer); |
44 | return false; |
45 | } |
46 | |
47 | /* Install new heap-based buffer. */ |
48 | buffer->data = new_ptr; |
49 | buffer->length = new_length; |
50 | return true; |
51 | } |
52 | libc_hidden_def (__libc_scratch_buffer_grow); |
53 | |