declare smobs in alloc.c
[bpt/emacs.git] / m4 / nocrash.m4
1 # nocrash.m4 serial 4
2 dnl Copyright (C) 2005, 2009-2014 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.
6
7 dnl Based on libsigsegv, from Bruno Haible and Paolo Bonzini.
8
9 AC_PREREQ([2.13])
10
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.
14 dnl Usage: ...
15 dnl ]GL_NOCRASH[
16 dnl ...
17 dnl int main() { nocrash_init(); ... }
18 AC_DEFUN([GL_NOCRASH],[[
19 #include <stdlib.h>
20 #if defined __MACH__ && defined __APPLE__
21 /* Avoid a crash on Mac OS 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>
27 #include <pthread.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
31 EXC_BAD_ACCESS. */
32 static void *
33 mach_exception_thread (void *arg)
34 {
35 /* Buffer for a message to be received. */
36 struct {
37 mach_msg_header_t head;
38 mach_msg_body_t msgh_body;
39 char data[1024];
40 } msg;
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)
46 abort ();
47 exit (1);
48 }
49 static void
50 nocrash_init (void)
51 {
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)
55 == KERN_SUCCESS) {
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)
59 == KERN_SUCCESS) {
60 /* The exceptions we want to catch. Only EXC_BAD_ACCESS is interesting
61 for us. */
62 exception_mask_t mask = EXC_MASK_BAD_ACCESS;
63 /* Create the thread listening on the exception port. */
64 pthread_attr_t attr;
65 pthread_t thread;
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);
78 }
79 }
80 }
81 }
82 #elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
83 /* Avoid a crash on native Windows. */
84 #define WIN32_LEAN_AND_MEAN
85 #include <windows.h>
86 #include <winerror.h>
87 static LONG WINAPI
88 exception_filter (EXCEPTION_POINTERS *ExceptionInfo)
89 {
90 switch (ExceptionInfo->ExceptionRecord->ExceptionCode)
91 {
92 case EXCEPTION_ACCESS_VIOLATION:
93 case EXCEPTION_IN_PAGE_ERROR:
94 case EXCEPTION_STACK_OVERFLOW:
95 case EXCEPTION_GUARD_PAGE:
96 case EXCEPTION_PRIV_INSTRUCTION:
97 case EXCEPTION_ILLEGAL_INSTRUCTION:
98 case EXCEPTION_DATATYPE_MISALIGNMENT:
99 case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
100 case EXCEPTION_NONCONTINUABLE_EXCEPTION:
101 exit (1);
102 }
103 return EXCEPTION_CONTINUE_SEARCH;
104 }
105 static void
106 nocrash_init (void)
107 {
108 SetUnhandledExceptionFilter ((LPTOP_LEVEL_EXCEPTION_FILTER) exception_filter);
109 }
110 #else
111 /* Avoid a crash on POSIX systems. */
112 #include <signal.h>
113 /* A POSIX signal handler. */
114 static void
115 exception_handler (int sig)
116 {
117 exit (1);
118 }
119 static void
120 nocrash_init (void)
121 {
122 #ifdef SIGSEGV
123 signal (SIGSEGV, exception_handler);
124 #endif
125 #ifdef SIGBUS
126 signal (SIGBUS, exception_handler);
127 #endif
128 }
129 #endif
130 ]])