1#include <signal.h>
2#include <unistd.h>
3#include <stdlib.h>
4#include <sys/mman.h>
5#include <stdio.h>
6#include <mach/mach.h>
7#include <mach/mach_vm.h>
8
9int *g_int_ptr = NULL;
10size_t g_size = 10*sizeof(int);
11
12void
13saction_handler(int signo, siginfo_t info, void *baton) {
14 printf(format: "Got into handler.\n"); // stop here in the signal handler
15 kern_return_t success
16 = mach_vm_protect(mach_task_self(), (mach_vm_address_t) g_int_ptr,
17 g_size, 0, VM_PROT_READ|VM_PROT_WRITE);
18 g_int_ptr[1] = 20;
19}
20int
21main()
22{
23 kern_return_t vm_result = vm_allocate(mach_task_self(), &g_int_ptr, g_size, VM_FLAGS_ANYWHERE);
24 for (int i = 0; i < 10; i++)
25 g_int_ptr[i] = i * 10;
26
27 vm_result = mach_vm_protect(mach_task_self(), (mach_vm_address_t) g_int_ptr, g_size, 0, VM_PROT_NONE);
28 struct sigaction my_action;
29 sigemptyset(set: &my_action.sa_mask);
30 my_action.sa_handler = (void (*)(int)) saction_handler;
31 my_action.sa_flags = SA_SIGINFO;
32
33 sigaction(SIGBUS, act: &my_action, NULL); // Stop here to get things going.
34 int local_value = g_int_ptr[1];
35 return local_value; // Break here to make sure we got past the signal handler
36}
37

source code of lldb/test/API/macosx/ignore_exceptions/main.c