BSD variables not declared? (jdk8 & jdk 9 builds)

[Kim Barrett]

> This might be of interest:
> https://gcc.gnu.org/gcc-4.4/porting_to.html
> Preprocessor conditionals always evaluated

Also see this:
http://lists.boost.org/Archives/boost/2011/08/184657.php

—————
This has come up before. The problem is with code like this: 

#if !defined(SOMETHING) 
#elif SOMETHING() == 1 
#endif 

In recent versions of gcc it fails when SOMETHING isn't defined 
because the 'SOMETHING() == 1' clause is always evaluated - even 
though the if statement has already been resolved. This is apparently 
compliant with the standard. 

The solution is to write: 

#if !defined(SOMETHING) 
#else 
# if SOMETHING() == 1 
# endif 
#endif

——————

That same technique could be applied by us, as an alternative to the proposed changes.
But it’s pretty annoying ugly, with sometimes long string of trailing #endif lines.