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Re: C99 support in Newlib

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
"%[...]" is supported, but "%[^...]" is not.
No, it is.  See libc/stdio/sccl.c.

Right, my mistake (; Sorry for the noise then (;


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

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:

    functions only part of the standard in C94 or above.
    functions only part of the standard in C99 or above.
    math complex functions only part of the standard in C99 or above.
    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
00000000 T sincos
00000000 T sincosf

Can someone confirm the support or lack thereof for these classes in
newlib for 'arm-none-eabi'.



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.


Attachment: missing
Description: Text document

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