Share via

Use Native Run-Time Checks

In a Visual Studio C++ project, 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

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 set the option in Visual Studio, see the Remarks section of the /RTC (Run-time error checks) reference article. Set the value in the Basic Runtime Checks property and not the Smaller Type Check property. The Smaller Type Check property is not recommended.

To modify native run-time check behavior

  • Use the runtime_checks pragma.