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

I needed this in a recent project, so I just built my own LLDB. I patched a line in tools/debugserver/source/MacOSX/MachTask.mm from

err = ::task_set_exception_ports (task, m_exc_port_info.mask, m_exception_port, EXCEPTION_DEFAULT | MACH_EXCEPTION_CODES, THREAD_STATE_NONE);

to

err = ::task_set_exception_ports (task, m_exc_port_info.mask & ~EXC_MASK_BAD_ACCESS, m_exception_port, EXCEPTION_DEFAULT | MACH_EXCEPTION_CODES, THREAD_STATE_NONE);

which causes the debugserver to be unable to catch EXC_BAD_ACCESS exceptions. Now, my custom LLDB works just fine: it still catches SIGSEGV and SIGBUS but no longer enters a silly infinite loop when faced with EXC_BAD_ACCESS. Setting process handle options on the previously-fatal signals works fine too, and I can now debug SEGV handlers with impunity.

Apple really ought to make this an option in LLDB...seems like a really easy fix for them.