How to stop Visual Studio from returning duplicates answers?

In my team, we put all our projects (only 7 large ones) in the same solution. And since some code is common between project we tend to have the same file included in each project. This is fine and compiles/runs well. But when I do a global searc开发者_如何转开发h in my solution, VS does a "stupid" search and goes through all the files in each project, without checking if a file has already been searched.

This leads to longer searches whose results have duplicates. Do anyone know a fix for this issue?

Why not put everything that's common to all projects in a project of its own, and link all the project against it? Shared functionality should be shared, not duplicated.