If it compile without problems

Right Click -> Index -> Refresh All Files

It should refresh its database of symbols
And the error should go away

Best Regards
Eng.Mazen Aljeddani

The problem was solved by understanding Eclipse illogic quircks and funny moves. It was caused by crossed out .c files which happened to be by default, crazy but true. I solved it by menu Project => Properties => C/C++ Build General => Paths and Symbols -> Source Location: Selecting path and Edit Filter. Beware Eclipse’s visibility to dependencies (inclusions and the likes) is set by multiple different Eclipse settings. Where one setting includes libraries (folders and/or files) another setting filters out sections of libraries (folders and files). And the beginning user not familiar with Eclipse’s oddities is left confused.

Thanks mazensaad. Had a similar problem, solved.
KR Martin