Re: glibc and cdefs.h

[Paul Eggert]

Bruno Haible wrote:
> IMO the only way to reliably use <libc-config.h> would be that after
> including it, you don't include any system headers any more.

Thanks for checking the port to FreeBSD 11. It appears that the problem is 
planned to go away in FreeBSD 12 (they've removed the cdefs.h __inline #define 
in their development version), so I hope this sort of thing is a one-off.

I guess you're suggesting two include files? config.h has to come first, so 
there'd be another include file (let's say, configlast.h) that would come last. 
I think something like that would work, though it would complicate the 
shared-with-glibc files a bit more, and even then it wouldn't be 100% reliable 
because system include files could define macros that are expanded after 
configlast.h is included.

If this is the only such problem we run into I'm not sure it's worth the hassle 
of having multiple includes. If we run into more such problems, we can keep this 
idea in reserve, though.

In the meantime this change got me to looking, and glibc has updated cdefs.h: 
it's fixed one portability bug that can let us simplify libc-config.h, has 
partially fixed another (not good enough, if you ask me), and added another 
macro. I would like to keep Gnulib cdefs.h in sync with glibc as much as 
possible, and installed the attached.

0001-libc-config-merge-from-glibc.txt
Description: Text document