How to find out what is causing an exception

Question

I've got a program that I am running with the VS debugger, and I am getting a number of exceptions like this:
Exception thrown at 0x00007FF8D5E7CD29 in RfidWinTest.exe: Microsoft C++ exception: unsigned long at memory location 0x0000009914CFDFE8.

How do I find out what is causing these? The debugger isn't stopping on my code. Some of them are followed by a thread closing.

Regards, Greg

Answer 1

The Visual Studio debugger allows you to configure it to break when exceptions are thrown. The settings are found in the Debug->Windows->Exception Settings window. For example,

I don't know if this will help in your particular situation. In the posted image I checked the "All C++ Exeptions Not in this list" box so that the debugger would break if an unsigned long was thrown.

You can test the settings -

   // CppException.cpp : This file contains the 'main' function. Program execution begins and ends there.  
   //  
     
   #include <iostream>  
   #include <stdexcept>  
     
     
   int main()  
   {  
       try  
       {  
           throw std::exception("C++ exception");  
       }  
       catch (const std::exception& ex)  
       {  
           std::cout << "Caught exception " << ex.what() << std::endl;  
       }  
     
       try  
       {  
           throw (unsigned long)42;  
       }  
       catch (unsigned long ul)  
       {  
           std::cout << "Caught exception " << ul << std::endl;  
       }  
     
       return 0;  
   }