Get some information from exception caught with catch(...)? [duplicate]

Question

I have a try catch clause where the outermost catch(...) never happened until now. After some changes, somewhere an exception which I don't handle with the other cases is thrown. Is there a way to get at least some information about the exception even though I catch it with (...)?

catch (const cone::BeginnersLibException& ex) 
{
    // handle the exception
}
catch (const std::exception& ex) 
{
    // handle std exception
} 
catch (...) 
{
    log("Unknown exception caught.");
    // How can I get more information about this exception?
}

---

Edit: here a code snippet that works for me:

#include <cxxabi.h>

// more code here 
} catch (...) {
    std::string exName(abi::__cxa_current_exception_type()->name());
    std::cout<<"unknown exception: "<< exName <<std::endl;
    throw;
}

Answer 1

You can do this using gdb or another debugger. Tell the debugger to stop when any exception is throw (in gdb the command is hilariously catch throw). Then you will see not only the type of the exception, but where exactly it is coming from.

Another idea is to comment out the catch (...) and let your runtime terminate your application and hopefully tell you more about the exception.

Once you figure out what the exception is, you should try to replace or augment it with something that does derive from std::exception. Having to catch (...) at all is not great.

If you use GCC or Clang you can also try __cxa_current_exception_type()->name() to get the name of the current exception type.