In a Visual Studio 2010 C/C++, what does the "Rescan Solution" operation do?

I'm trying to compile a third-party project and I'm getting a fe开发者_C百科w linking issues. I'm not having much trouble fixing the minor issues but I noticed their was a "Rescan Solution" option in the context menu of the project or solution.

I clicked it but it didn't seem to do anything. What, exactly, does it do?

This command updates out-of-date files in the project browsing database. Nothing to do with compilation/linking problems.