Re: [RFC] Make _FILE_OFFSET_BITS=64 default.

[Paul Eggert <eggert at cs dot ucla dot edu>]

Joseph S. Myers wrote:

> I certainly don't think they should be overriding _Static_assert provided by GCC (>= 4.6)

Good point, thanks.  Revised patches attached.

> I don't think the installed glibc headers should be providing _Static_assert

It's what FreeBSD <sys/cdefs.h> does, and applications seem to be doing 
fine there.  So there's good precedent, it's not risky, and it would 
improve compatibility with FreeBSD.

> arguably assert.h should try to do something for the case
> of _ISOC11_SOURCE, non-C11 compiler

That wouldn't support one of the main attractions of _Static_assert, 
namely that it works even when <assert.h> isn't included.  Application 
writers will prefer this feature, and defining _Static_assert in cdefs.h 
gets us close enough to this goal to be reasonably useful in apps 
compiled with pre-C11 compilers.

> generally that applies to any compiler possibly providing
> _Static_assert outside C11 mode - the library shouldn't get in the way of
> the user using the compiler feature

In general that's a good principle, but here there's not much to get in 
the way of, as the glibc substitute does the job even when it takes over 
from Clang etc.  If there's consensus I could add the usual forest of 
#ifs so as to not #define _Static_assert in non-GCC pre-C11 compilers 
where _Static_assert is known to work, but that's not what we've done in 
similar situations elsewhere in glibc, and there is some virtue in 
simplicity.

Attachment: 0001-Approximate-_Static_assert-for-pre-C11-compilers.patch
Description: Text document

Attachment: 0002-fts-allow-_FILE_OFFSET_BITS-64-on-64-bit-hosts.patch
Description: Text document