Regression with printf 8-bit format macros

Ambroz Bizjak
Fri Jan 1 23:04:00 GMT 2016

Hi Freddie,

I hope we agree that C99 support should not be an all-or-nothing
decision, you should be able to have some parts (like the stdint types
which cost nothing), but not other parts like the full C99 support in
printf. The worst part really is that the PRI*8 macros are defined in
the mentioned configurations but they do not work. I see that on the
other hand the SCN*8 macros are not defined when they would not work
(see the top comment in inttypes.h).

But then we can have the PRI*8 macros for free anyway, so why should
they be available only when printf has "hh" support?

Best regards,

On Fri, Jan 1, 2016 at 11:44 PM, Freddie Chopin <> wrote:
> On piątek, 1 stycznia 2016 12:08:30 CET Ambroz Bizjak wrote:
>> Hello,
>> It appears to me that commit "Fix for pri and scn formats" [1] broke
>> the 8-bit printf format macros (PRI*8), for scenarios when newlib is
>> configured either with --enable-newlib-nano-formatted-io or without
>> --enable-newlib-io-c99-format is not used. Because the new code
>> defines these macros to the "hh" formats, which are not supported
>> then.
> Is it actually a problem that PRI* macros don't work without support for C99?
> After all, these are used for C99 types, so not really needed without C99...
> Regards,
> FCh

More information about the Newlib mailing list