On Tue, Sep 25, 2012 at 05:57:08PM -0700, Paul Eggert wrote:
> On 09/25/2012 05:04 PM, Adrian Bunk wrote:
> > If a future gcc version
> > ...
> > supports C11 features in gnu11 mode it doesn't support in
> > gnu99 mode (likely)
>
> I don't see this as likely, as I don't see any such features on the
> horizon. (I am excluding gets, which we don't want to be encouraging anyway.)
You assume gnu99 will always include all features of gnu11?
> > Currently gcc is the only compiler where autoconf knows how to put it
> > into C11 mode, and __STDC_VERSION__ is defined in gnu11 mode.
>
> But gcc normally doesn't define __STDC_VERSION__. Granted,
> gcc --std=gnu11 does define it, but all in all __STDC_VERSION__
> is a bit squirrelly and I'd rather not be using it as part of a test.
gcc defines __STDC_VERSION__ except for pre-C94 modes like gnu89 (which
is the default), since __STDC_VERSION__ was not defined in the original C89.
Notes:
- we are discussing here only C11 mode detection and setting
- currently gcc >= 4.7 is the only compiler supported for that in
autoconf
- there is the option to make that part of the check gcc-only later if
it would turn out that this is needed when C11 setting for other
compilers will get added.
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
