/GX (Enable Exception Handling)
Enables synchronous exception handling with the assumption that extern C functions never throw an exception.
It is equivalent to /EH (Exception Handling Model).
/GX is in effect, by default, when you compile from within the development environment. By default, /GX- is enabled when using command-line tools.
For more information, see C++ Exception Handling.
To set this compiler option in the Visual Studio development environment
Open the project's Property Pages dialog box. For details, see How to: Open Project Property Pages.
Click the C/C++ folder.
Click the Command Line property page.
Type the compiler option in the Additional Options box.
To set this compiler option programmatically