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
|
/* This test program is part of GDB, the GNU debugger.
Copyright 2015-2021 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <stdlib.h>
typedef void (*callback_t) (void);
extern void process (callback_t cb);
extern void parent (int first, callback_t cb);
void
ignore (int unused)
{
(void) unused;
}
void
process (callback_t cb)
{
parent (0, cb);
}
void
parent (int first, callback_t cb)
{
void child (void)
{
/* When reaching this, there are two block instances for PARENT on the
stack: the one that is right in the upper frame is not the one actually
used for non-local references, so GDB has to follow the static link in
order to get the correct instance, and thus in order to read the proper
variables.
As a simple check, we can verify that under GDB, the following is true:
parent_first == first (which should be one: see the IF block below). */
const int parent_first = first;
ignore (parent_first); /* STOP */
ignore (first);
}
if (first)
process (&child);
else
cb ();
}
int
main ()
{
parent (1, NULL);
return 0;
}
|
