How to make lldb ignore EXC_BAD_ACCESS exception?

Question

I am writing a program on Mac OSX depending on the sigaction/sa_handler mechanism. Run a code snippet from user and get ready to catch signals/exceptions at any time. The progra

Answer 1

A little bit of example code can make a question like this a lot easier to answer ... I've never used the sigaction API before but I threw this together -

#include 
#include 
#include 

void segv_handler (int in)
{
    puts ("in segv_handler()");
}

void sigbus_handler (int in)
{
    puts ("in sigbus_handler()");
}

int main ()
{
    struct sigaction action;
    action.sa_mask = 0;
    action.sa_flags = 0;


    action.sa_handler = segv_handler;
    sigaction (SIGSEGV, &action, NULL);
    action.sa_handler = sigbus_handler;
    sigaction (SIGBUS, &action, NULL);

    puts ("about to send SIGSEGV signal from main()");
    kill (getpid(), SIGSEGV);

    puts ("about to send SIGBUS signal from main()");
    kill (getpid(), SIGBUS);

    puts ("exiting main()");

}


% lldb a.out
(lldb) br s -n main
(lldb) r
(lldb) pr h -p true -s false SIGSEGV SIGBUS
(lldb) c
Process 54743 resuming
about to send SIGSEGV signal from main()
Process 54743 stopped and restarted: thread 1 received signal: SIGSEGV
in segv_handler()
about to send SIGBUS signal from main()
Process 54743 stopped and restarted: thread 1 received signal: SIGBUS
in sigbus_handler()
exiting main()
Process 54743 exited with status = 0 (0x00000000) 
(lldb) 

Everything looks like it's working correctly here. If I'd added -n false to the process handle arguments, lldb wouldn't have printed the lines about Process .. stopped and restarted.

Note that these signal settings do not persist across process executions. So if you're starting your debug session over (r once you've already started the process once), you'll need to re-set these. You may want to create a command alias shortcut and put it in your ~/.lldbinit file so you can set the process handling the way you prefer with a short cmd.