Eclipse C/C++ Shows Errors but Compiles?
So I am building some Arduino code in eclipse, as described in Your Second Arduino Project, but every time I use an Arduino library, such as Serial, Eclipse underlines my function names, claiming they cannot be resolved. However, the code actually compiles, so I'm kind of at a loss as to why Eclipse thinks the functions are missing. If anyone has any idea on how to solve this problem it would be appreciated. Thanks beforehand.
EDIT: I should have been more specific, Eclipse underlines the METHODS inside the Arduino libraries. So if I use Serial.println("hello");, it underlines println() and claims it cannot be resolved. Then it compiles just fine and the method works when uploaded to the arduino board.
EDIT2: I found my error, turns out I was trying to use some C++ functions in a C file, and eclipse didn't like it; I renamed to .cpp and all the red disappeared ;) Thanks for your help!
Answer
Eclipse may or may not be pulling the paths to index from your build setup, depending on the configuration. Most likely, it is not...it's building correctly because your build setup is just fine, and you can probably build by hand.
The CDT indexer (which is the engine for deciding where all those pretty underlines, as well as code completion, F3 declaration jumping, etc comes from) isn't smart enough in a lot of cases to parse out your Makefiles and know where to look for headers and source. You need to tell Eclipse that information manually.
Go to Project Properties -> C/C++ General -> Paths and Symbols.
The amount of work you need to put into this can vary greatly, depending on your environment. If this external library is the only thing giving you headaches, then you probably just need to add the paths for that library and reindex:
Right-click on the project and select Index -> Rebuild