1/* This testcase is part of GDB, the GNU debugger.
2
3   Copyright 1996, 1999, 2003, 2004 Free Software Foundation, Inc.
4
5   This program is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 2 of the License, or
8   (at your option) any later version.
9
10   This program 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
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program; if not, write to the Free Software
17   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
18   02111-1307, USA.  */
19
20#include <signal.h>
21#include <setjmp.h>
22#include <stdlib.h>
23#include <string.h>
24
25enum tests {
26  code_entry_point, code_descriptor, data_read, data_write
27};
28
29static volatile enum tests test;
30
31/* Some basic types and zero buffers.  */
32
33typedef long data_t;
34typedef long code_t (void);
35data_t *volatile data;
36code_t *volatile code;
37/* "desc" is intentionally initialized to a data object.  This is
38   needed to test function descriptors on arches like ia64.  */
39data_t zero[10];
40code_t *volatile desc = (code_t *) (void *) zero;
41
42sigjmp_buf env;
43
44extern void
45keeper (int sig)
46{
47  siglongjmp (env, 0);
48}
49
50extern long
51bowler (void)
52{
53  switch (test)
54    {
55    case data_read:
56      /* Try to read address zero.  */
57      return (*data);
58    case data_write:
59      /* Try to write (the assignment) to address zero.  */
60      return (*data) = 1;
61    case code_entry_point:
62      /* For typical architectures, call a function at address
63	 zero.  */
64      return (*code) ();
65    case code_descriptor:
66      /* For atypical architectures that use function descriptors,
67	 call a function descriptor, the code field of which is zero
68	 (which has the effect of jumping to address zero).  */
69      return (*desc) ();
70    }
71}
72
73int
74main ()
75{
76  static volatile int i;
77
78  struct sigaction act;
79  memset (&act, 0, sizeof act);
80  act.sa_handler = keeper;
81  sigaction (SIGSEGV, &act, NULL);
82
83  for (i = 0; i < 10; i++)
84    {
85      sigsetjmp (env, 1);
86      bowler ();
87    }
88}
89