[PATCH 1/7] Fix __PTHREAD_MUTEX_HAVE_ELISION -Wundef warning

[Joseph S. Myers]

On Thu, 20 Mar 2014, Roland McGrath wrote:

> > Typo-proofing also provides another case for replacing the __need_* 
> > scheme, as I suggested in 
> > <https://sourceware.org/ml/libc-alpha/2012-08/msg00510.html> and 
> > <https://sourceware.org/ml/libc-alpha/2012-11/msg00045.html>, so that we 
> > do
> > 
> > #include <bits/time_t.h>
> > 
> > instead of
> > 
> > #define __need_time_t
> > #include <time.h>
> > 
> > (the former being typo-proof, the latter not).
> 
> I didn't recall you suggesting that, but it's been on my list for some
> time.  (I think we should use a convention other than plain bits/, but
> that's just trivia.)

Note that for the cases of

#define __need_size_t
#include <stddef.h>

and other cases involving stddef.h, an improvement would require new 
separate headers to be installed by GCC, so that glibc's header for size_t 
could do

#if __GNUC_PREREQ (whatever)
# include <gcc-size_t.h>
#else
# define __need_size_t
# include <stddef.h>
#endif

or similar.

-- 
Joseph S. Myers
joseph@codesourcery.com