bug#8881: config.h double inclusion

[Paul Eggert]

On 06/16/11 10:36, Alfred M. Szmidt wrote:
> I'm thinking that maybe <config.h> should be generated with a double
> inclusion guard

But the general rule is that <config.h> must always be included first, no?
So there shouldn't ever be a possibility of including it twice.

It might be better to have config.h do something like this:

#ifdef CONFIG_H
# error "config.h included twice"
#endif
#define CONFIG_H


> A bit later, we do:
> 
>   #include <libinetutils.h>
> 
> which will cause warnings like:
> 
>   ../config.h:561:1: warning "HAVE_DECL_PROGRAM_INVOCATION_NAME" redefined

Sp libinetutils.h includes config.h?  Then that is a problem.
One possible fix is to arrange for libinetutils.h to be built from
libinetutils.in.h, the same way that (for example) stdint.h is built
from stdint.in.h in gnulib.