Re: C99 support in Newlib

["Andre Vieira (lists)" <Andre dot SimoesDiasVieira at arm dot com>]

On 11/01/16 14:27, Andre Vieira (lists) wrote:
> On 20/01/15 11:49, Freddie Chopin wrote:
> > On 01/20/2015 12:46 PM, Corinna Vinschen wrote:
> > > On Jan 20 12:21, Freddie Chopin wrote:
> > > > On 01/20/2015 11:06 AM, Corinna Vinschen wrote:
> > > > > On Jan 20 17:19, Joey Ye wrote:
> > > > > > Corinna, May I know which features are missing please?
> > > > > As far as I can tell, mainly the long double functions for targets
> > > > > with sizeof(double) != sizeof(long double).
> > > > I have one more - from my recent browsing of scanf() code, I assume
> > > > that
> > > > "%[...]" is supported, but "%[^...]" is not.
> > > No, it is.  See libc/stdio/sccl.c.
> >
> > Right, my mistake (; Sorry for the noise then (;
> >
> > Regards,
> > FCh
>
> Hi there,
>
> I thought I'd reply to this thread as it is very much related to my issue.
>
> In a recent GCC patch a change to an optimization, which now checks for
> the existence of libc support for C99 functions, lead to a regression
> for arm-none-eabi. This is because currently GCC is set up to assume no
> C99 support is available for arm-none-eabi. As far as I know this is
> because it comes with newlib and as this thread points out it does not
> claim to fully support C99. See
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69227
>
> Hopefully with some help I can figure out what GCC 'function classes'
> can be seen as supported by newlib for arm-none-eabi. These function
> classes are:
>
> function_c94:
>     functions only part of the standard in C94 or above.
> function_c99_misc:
>     functions only part of the standard in C99 or above.
> function_c99_math_complex:
>     math complex functions only part of the standard in C99 or above.
> function_c11_misc:
>     functions only part of the standard in C11 or above
>
> And there is also 'function_sincos' for which I couldn't find a
> definition though I assume its for the GNU extension 'sincos'.
>
> $arm-none-eabi-nm libm.a | grep sincos
> lib_a-w_sincos.o:
> 00000000 T sincos
> lib_a-wf_sincos.o:
> 00000000 T sincosf
>
>
> Can someone confirm the support or lack thereof for these classes in
> newlib for 'arm-none-eabi'.
>
> Thanks!
>
> BR,
> Andre

As an investigation exercise I constructed a list of all functions in 
the C99 standard and I checked whether the newlib version we build for 
arm-none-eabi defined these and I found that it was missing quite a lot 
of them! See attached file.

That answers my question for the bugzilla ticket. We can not enable 
function_c99_* function class support for arm-none-eabi.

Cheers,
Andre

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