How to: Use Native Run-Time Checks

Note

This article applies to Visual Studio 2015. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here

In Visual C++, you can use native runtime_checks to catch common run-time errors such as:

  • Stack pointer corruption.

  • Overruns of local arrays.

  • Stack corruption.

  • Dependencies on uninitialized local variables.

  • Loss of data on an assignment to a shorter variable.

    If you use /RTC with an optimized (/O) build, a compiler error results. If you use a runtime_checks pragma in an optimized build, the pragma has no effect.

    When you debug a program that has run-time checks enabled, the default action is for the program to stop and break to the debugger when a run-time error occurs. You can change this default behavior for any run-time check. For more information, see Managing Exceptions with the Debugger.

    The following procedures describe how to enable native run-time checks in a debug build, and how to modify native run-time check behavior.

    Other topics in this section provide information about:

  • Customizing Run-Time Checks with the C Run-Time Library

  • Using Run-Time Checks without the C Run-Time Library

To enable native run-time checks in a debug build

  • Use the /RTC option and link with the debug version of a C run-time library (/MDd, for example).

To modify native run-time check behavior

  • Use the runtime_checks pragma.

See Also

Debugging in Visual Studio
runtime_checks
Run-Time Error Checking