2 dnl Copyright (C) 2005, 2009-2011 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 dnl Based on libsigsegv, from Bruno Haible and Paolo Bonzini.
11 dnl Expands to some code for use in .c programs that will cause the configure
12 dnl test to exit instead of crashing. This is useful to avoid triggering
13 dnl action from a background debugger and to avoid core dumps.
17 dnl int main() { nocrash_init(); ... }
18 AC_DEFUN([GL_NOCRASH],[[
20 #if defined __MACH__ && defined __APPLE__
21 /* Avoid a crash on MacOS X. */
22 #include <mach/mach.h>
23 #include <mach/mach_error.h>
24 #include <mach/thread_status.h>
25 #include <mach/exception.h>
26 #include <mach/task.h>
28 /* The exception port on which our thread listens. */
29 static mach_port_t our_exception_port;
30 /* The main function of the thread listening for exceptions of type
33 mach_exception_thread (void *arg)
35 /* Buffer for a message to be received. */
37 mach_msg_header_t head;
38 mach_msg_body_t msgh_body;
41 mach_msg_return_t retval;
42 /* Wait for a message on the exception port. */
43 retval = mach_msg (&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE, 0, sizeof (msg),
44 our_exception_port, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
45 if (retval != MACH_MSG_SUCCESS)
52 mach_port_t self = mach_task_self ();
53 /* Allocate a port on which the thread shall listen for exceptions. */
54 if (mach_port_allocate (self, MACH_PORT_RIGHT_RECEIVE, &our_exception_port)
56 /* See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/mach_port_insert_right.html. */
57 if (mach_port_insert_right (self, our_exception_port, our_exception_port,
58 MACH_MSG_TYPE_MAKE_SEND)
60 /* The exceptions we want to catch. Only EXC_BAD_ACCESS is interesting
62 exception_mask_t mask = EXC_MASK_BAD_ACCESS;
63 /* Create the thread listening on the exception port. */
66 if (pthread_attr_init (&attr) == 0
67 && pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED) == 0
68 && pthread_create (&thread, &attr, mach_exception_thread, NULL) == 0) {
69 pthread_attr_destroy (&attr);
70 /* Replace the exception port info for these exceptions with our own.
71 Note that we replace the exception port for the entire task, not only
72 for a particular thread. This has the effect that when our exception
73 port gets the message, the thread specific exception port has already
74 been asked, and we don't need to bother about it.
75 See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/task_set_exception_ports.html. */
76 task_set_exception_ports (self, mask, our_exception_port,
77 EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
83 /* Avoid a crash on POSIX systems. */
85 /* A POSIX signal handler. */
87 exception_handler (int sig)
95 signal (SIGSEGV, exception_handler);
98 signal (SIGBUS, exception_handler);