Supported Code Changes

This topic applies to:


Visual Basic





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Edit and Continue handles most types of code changes. However, some changes cannot be applied during program execution. To apply these changes, you must stop execution and build a fresh version of the code.

The following C/C++ changes cannot be applied during a debugging session:

  • Most changes to global or static data.

  • Changes to executables that are copied from another machine and not built locally.

  • Changes to a data type that affect the layout of an object, such as data members of a class.

  • Adding more than 64k bytes of new code or data.

  • Adding variables that require a constructor at a point before the instruction pointer.

  • Changes that affect code that requires run-time initialization.

  • Adding exception handlers, in some instances.

  • Changes to resource files.

  • Changes to code in read-only files.

  • Changes to code without a corresponding PDB file.

  • Changes to code that has no object file.

If you make one of these changes and then try to apply code changes, an error or warning message appears in the Output window.

  • Edit and Continue does not update static libraries. If you make a change in a static library, execution continues with the old version and no warning is issued.

Unsupported Scenarios

Edit and Continue is unavailable in the following debugging scenarios:

  • Debugging on Windows 98.

  • Mixed-mode (native/managed) debugging.

  • SQL debugging.

  • Debugging a Dr. Watson dump.

  • Editing code after an unhandled exception, when the Unwind the call stack on unhandled exceptions option is not selected.

  • Debugging an application by using Attach to instead of running the application by clicking Start on the Debug menu.

  • Debugging optimized code.

  • Debugging managed code when the target is a 64-bit application. If you want to use Edit and Continue, you must set the target to x86. (Project Properties, Compile tab, Advanced Compiler setting.).

  • Debugging an old version of your code after a new version failed to build because of build errors.

See Also


Edit and Continue, Debugging, Options Dialog Box


Edit and Continue