Eclipse CDT graying out wrong part of code under #ifndef

Question

I have header base.h containing

#ifndef GUARD_H
#define GUARD_H

<my code>

#endif

Eclipse CDT is graying out everything below #ifndef GUARD_H . This would be correct if GUARD_H were defined, but it is not. Actually, the only place where it is defined across my system is the following line, precisely as intended for an include guard. So, I cannot see why this happens.

Moreover, among the hundreds of headers I used under Eclipse CDT in my life, and in particular under the present project, this is the first time I see such a thing.

Why does this happen? How can I fix this?

Using Eclipse IDE for C/C++ Developers, Version: 2018-09 (4.9.0), Build id: 20180917-1800 under Win 10.

Answer 1

As per this comment , adding affected headers to Preferences -> C/C++ -> Indexer -> Index all variants of specific headers (separated by semicolon) helps. "Index all header variants" can also help but at a possible performance cost.

I found it sometimes works. Sometimes it doesn't, but it starts working at a later time while I am coding or navigating, without any apparent specific action on my side. Also the opposite, sometimes code becomes greyed out, without any apparent specific action on my side.

Answer 2

Found this serendipitously. Changing affected headers to something like

#ifndef GUARD_H
#define GUARD_H

<my code>

#endif // GUARD_H   <-- Modification

did the job in a few cases I tried.