Development with Eclipse - Wrong error messages in IDE

Good morning hackers,
I have some strange error message inside Eclipse, that some symbols 
cannot be found. I work with version 9.6 currently. For instance,

Symbol 'RM_HEAP_ID' could not be resolved
src/backend/access/heap/heapam.c

It affects all occurrences of symbols that are defined in
src/include/access/rmgrlist.h. Eclipse just says "Syntax error" here.

However, the source code compiles and runs without any compile-time 
error or warning. It is just an IDE problem I think, but it distracts me 
from finding real bugs.

Does anyone had similar problems? Do I have to configure Eclipse to 
understand the PG_RMGR macro or is there another possibility to teach 
Eclipse these macros?

Thanks for any help or comment.

Best regards,
Peter