catch(...) is not catching an exception, my program is still crashing

Question

I'm having a problem with a tester that my application crashes in initialization. I added more logging and exception handling but it still crashes with the generic "this program has stopped working" message rather than triggering my error handling.

Given my main() looks like this and has catch(...) under what circumstances would this not be triggered?

try{
    simed::CArmApp app(0, cmd);
    for(bool done = false;!done;) 
    {
        done = !app.frame();
    }
} catch(const std::runtime_error &e){
    handleApplicationError(e.what());
    return -1;
} catch(...) {
    handleApplicationError("Unknown Error");
    return -999;
}

My code is calling into a library doing OpenGL rendering which is where I believe things are going wrong.

Answer 1

If a C++ catch(...) block is not catching errors maybe it is because of a Windows error.

On Windows there is a concept called Structured Exception Handling which is where the OS raises "exceptions" when bad things happen such as dereferencing a pointer that is invalid, dividing by zero etc. I say "exceptions" because these are not C++ exceptions; rather these are critical errors that Windows defines in a C-style fashion - this is because Win32 was written in C so C++ exceptions were not viable.

See also:

• Difference between a C++ exception and Structured Exception
• try-except Statement
• Method of getting a stack trace from an EXCEPTION_POINTERS struct

Update based on comments

If you want both C++ exception handing and SEH perhaps you could try the following (untested) code:

__try
{
    try
    {
        // Your code here...
    }
    catch (std::exception& e)
    {
        // C++ exception handling
    }
}
__except(HandleStructuredException())
{
    // SEH handling 
}

Answer 2

If an exception is thrown by the destructor of an object that is destroyed as a result of the stack unwinding to handle a different exception, the program will exit, catch(...) or not.

Answer 3

So far I know, there can be at least two situations where catch(...) cannot actually catch

1. More than 1 unhandled Exception: when an exception is raised before a previously occurred exception is handled, then c++ can not handle it, and application will crash.
2. Throwing exception that is not in exception specification list: if any method throws an exception which is not in the exception specification list (in any) then unexpected will be called which calls abort.

Answer 4

Do you declare any global objects? If you have any objects created outside your main loop, that could explain why it is not caught ( it is not in your try-catch ).