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
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
/* libguestfs
* Copyright (C) 2013 Red Hat Inc.
*
* This 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 of the License, or (at your option) any later version.
*
* This 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* Libguestfs uses C<CLEANUP_*> macros to simplify temporary
* allocations. They are implemented using the
* C<__attribute__((cleanup))> feature of gcc and clang. Typical
* usage is:
*
* fn ()
* {
* CLEANUP_FREE char *str = NULL;
* str = safe_asprintf (g, "foo");
* // str is freed automatically when the function returns
* }
*
* There are a few catches to be aware of with the cleanup mechanism:
*
* =over 4
*
* =item *
*
* If a cleanup variable is not initialized, then you can end up
* calling L<free(3)> with an undefined value, resulting in the
* program crashing. For this reason, you should usually initialize
* every cleanup variable with something, eg. C<NULL>
*
* =item *
*
* Don't mark variables holding return values as cleanup variables.
*
* =item *
*
* The C<main()> function shouldn't use cleanup variables since it is
* normally exited by calling L<exit(3)>, and that doesn't call the
* cleanup handlers.
*
* =back
*
* The functions in this file are used internally by the C<CLEANUP_*>
* macros. Don't call them directly.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "guestfs-utils.h"
/* Stdlib cleanups. */
void
guestfs_int_cleanup_free (void *ptr)
{
free (* (void **) ptr);
}
void
guestfs_int_cleanup_unlink_free (char **ptr)
{
char *filename = *ptr;
if (filename) {
unlink (filename);
free (filename);
}
}
void
guestfs_int_cleanup_close (void *ptr)
{
const int fd = * (int *) ptr;
if (fd >= 0)
close (fd);
}
void
guestfs_int_cleanup_fclose (void *ptr)
{
FILE *f = * (FILE **) ptr;
if (f)
fclose (f);
}
void
guestfs_int_cleanup_pclose (void *ptr)
{
FILE *f = * (FILE **) ptr;
if (f)
pclose (f);
}
void
guestfs_int_cleanup_free_string_list (char ***ptr)
{
guestfs_int_free_string_list (*ptr);
}
|
