问题
What does this special folder icon in CDT/Eclipse project explorer mean? The bluish thingy looks like a key or screw or some kind of tool. I guess it has something to do with CVS. I couldn't find the info in the Preferences > Appearance > Label Decorations settings.
回答1:
The wrench icon over a folder or file means that it is overriding some of the build settings inherited from its parent. If it's there by accident, you most likely right-clicked that folder instead of the entire project and changed some of its properties.
To fix it, right click the folder with the wrench icon, go to its properties, and click "restore defaults" on each of the categories that differ from the main project.
回答2:
That seems to be custom resource setting, also shown in the CDT 7.0 release news (do a page search for overlay).
回答3:
When you have a include path pointed into a directory, then that directory will have a key symbol
来源：https://stackoverflow.com/questions/11796235/what-is-the-meaning-of-this-decorated-folder-icon-in-eclipse-cdt-project-explore