Gtest-exc.c revision 757746aefbc6edfc77bde6a66ed251b4e1d5c46d 
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  void *label;
99
100  if (verbose)
101    printf ("a: sp=%p bsp=%p\n", &stack, __builtin_ia64_bsp ());
102#ifdef UNW_TARGET_IA64
103  asm ("movl %0=Label" : "=r"(label));
104#else
105  label = &&handler;
106#endif
107  b (label);
108  panic ("FAILURE: unexpected return from func()!\n");
109
110#if UNW_TARGET_IA64
111  asm volatile ("Label:");	/* force a new bundle */
112#else
113  handler:
114#endif
115  if (verbose)
116    {
117      printf ("exception handler: here we go (sp=%p, bsp=%p)...\n",
118	      &stack, __builtin_ia64_bsp ());
119      /* This call works around a bug in gcc (up-to pre3.4) which
120	 causes invalid assembly code to be generated when
121	 __builtin_ia64_bsp() gets predicated.  */
122      getpid ();
123    }
124#else
125  if (verbose)
126    printf ("a: this test only works with GNU C compiler.\n");
127#endif
128  return 0;
129}
130
131static void
132b (void *addr)
133{
134  if (verbose)
135    printf ("b() calling raise_exception()\n");
136  raise_exception (addr);
137  panic ("FAILURE: b() returned from raise_exception()!!\n");
138}
139
140int
141main (int argc, char **argv)
142{
143  if (argc > 1)
144    ++verbose;
145
146  if (a () != 0 || nerrors > 0)
147    {
148      fprintf (stderr, "FAILURE: test failed; try again?\n");
149      exit (-1);
150    }
151
152  if (verbose)
153    printf ("SUCCESS!\n");
154  return 0;
155}
156