It is extremely, let me repeat extremely, important that your code generator should include the name of the source file or files as part of the Don't edit this, it's generated warning at the top of the output.

By way of a negative example, this

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:2.0.50727.42
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated> //------------------------------------------------------------------------------

//
// This source code was auto-generated by Microsoft.VSDesigner, Version 2.0.50727.42.