Question

I have a process which I start with CreateProcess, then I wait for it to finish and check its exit code. I do this in batch mode and I don’t want any message boxes to show up if the process crashes. It’s enough to just return a nonzero exit code which would indicate failure. So far I’ve tried using

LONG WINAPI MyUnhandledExceptionFilter(_EXCEPTION_POINTERS *lpTopLevelExceptionFilter)
{
    ExitProcess(-1);
    return EXCEPTION_EXECUTE_HANDLER;
}

BOOL CMyApp::InitInstance()
{
    AfxEnableControlContainer();

    SetUnhandledExceptionFilter(MyUnhandledExceptionFilter);

    throw std::runtime_error("test");
}

But this isn’t always silent. Sometimes it displays a dialog:

---------------------------
Microsoft Visual C++ Runtime Library
---------------------------
Runtime Error!

Program: C:\Workspace\MyApp\Release\MyApp.exe



abnormal program termination


---------------------------
OK   
---------------------------

Answer 1

You want to suppress two things:

1. OS modal dialog notifying user on crash
2. Your own dialogs popped up by runtime

The first you do with SetErrorMode requesting SEM_FAILCRITICALERRORS and SEM_NOGPFAULTERRORBOX. The second can be suppressed by altering CRT behavior with _set_abort_behavior.

You don’t actually need an empty handler with SetUnhandledExceptionFilter – you are not doing anything important there. Proving no handler would crash the process and SetErrorMode (see above) will suppress the unwanted OS notification.

Sample code to do it:

SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);
_set_abort_behavior(0,_WRITE_ABORT_MSG);