Gtest-exc.c revision 797322b3b461c7e71d1d072227b5aa65a9ff31fa 
1/* libunwind - a platform-independent unwind library
2   Copyright (C) 2001-2003 Hewlett-Packard Co
3	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4
5Permission is hereby granted, free of charge, to any person obtaining
6a copy of this software and associated documentation files (the
7"Software"), to deal in the Software without restriction, including
8without limitation the rights to use, copy, modify, merge, publish,
9distribute, sublicense, and/or sell copies of the Software, and to
10permit persons to whom the Software is furnished to do so, subject to
11the following conditions:
12
13The above copyright notice and this permission notice shall be
14included in all copies or substantial portions of the Software.
15
16THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
23
24/* This illustrates the basics of using the unwind interface for
25   exception handling.  */
26
27#include <stdio.h>
28#include <stdlib.h>
29#include <unistd.h>
30
31#include <libunwind.h>
32
33#define panic(args...)				\
34	{ ++nerrors; fprintf (stderr, args); }
35
36int nerrors = 0;
37int verbose = 0;
38
39static void b (void *);
40
41static void
42raise_exception (void *addr)
43{
44  unw_cursor_t cursor;
45  unw_word_t ip;
46  unw_context_t uc;
47
48  unw_getcontext (&uc);
49  if (unw_init_local (&cursor, &uc) < 0)
50    {
51      panic ("unw_init_local() failed!\n");
52      return;
53    }
54
55  /* unwind to frame b(): */
56  if (unw_step (&cursor) < 0)
57    {
58      panic ("unw_step() failed!\n");
59      return;
60    }
61
62  /* unwind to frame a(): */
63  if (unw_step (&cursor) < 0)
64    {
65      panic ("unw_step() failed!\n");
66      return;
67    }
68
69  unw_get_reg (&cursor, UNW_REG_IP, &ip);
70  if (verbose)
71    printf ("old ip = %lx, new ip = %p\n", (long) ip, addr);
72
73  if (unw_set_reg (&cursor, UNW_REG_IP, (unw_word_t) addr) < 0)
74    {
75      panic ("unw_set_reg() failed!\n");
76      return;
77    }
78
79  unw_resume (&cursor);	/* transfer control to exception handler */
80}
81
82#if !UNW_TARGET_IA64
83
84void *
85__builtin_ia64_bsp (void)
86{
87  return NULL;
88}
89
90#endif
91
92static int
93a (void)
94{
95  long stack;
96
97#ifdef __GNUC__
98  if (verbose)
99    printf ("a: sp=%p bsp=%p\n", &stack, __builtin_ia64_bsp ());
100  b (&&handler);
101  panic ("FAILURE: unexpected return from func()!\n");
102
103#if UNW_TARGET_IA64
104  asm volatile ("1:");	/* force a new bundle */
105#endif
106 handler:
107  if (verbose)
108    {
109      printf ("exception handler: here we go (sp=%p, bsp=%p)...\n",
110	      &stack, __builtin_ia64_bsp ());
111      /* This call works around a bug in gcc (up-to pre3.4) which
112	 causes invalid assembly code to be generated when
113	 __builtin_ia64_bsp() gets predicated.  */
114      getpid ();
115    }
116#else
117  if (verbose)
118    printf ("a: this test only works with GNU C compiler.\n");
119#endif
120  return 0;
121}
122
123static void
124b (void *addr)
125{
126  if (verbose)
127    printf ("b() calling raise_exception()\n");
128  raise_exception (addr);
129  panic ("FAILURE: b() returned from raise_exception()!!\n");
130}
131
132int
133main (int argc, char **argv)
134{
135  if (argc > 1)
136    ++verbose;
137
138  if (a () != 0 || nerrors > 0)
139    {
140      fprintf (stderr, "FAILURE: test failed; try again?\n");
141      exit (-1);
142    }
143
144  if (verbose)
145    printf ("SUCCESS!\n");
146  return 0;
147}
148