How do I find files that are missing from visual studio projects?

Question

Due to issues with merging etc, we have lots of project files that don’t contain all source code files that are within their folders.

Before I write a little tool, that

Answer 1

We had a similar situation which resulted in failed compiles due to missing files. I stumbled upon this post linked below, which helped me. It describes writing a Visual Studio macro that runs when a build is started.

Report error/warning if missing files in project/solution in Visual Studio