Re: nano printf + powerpc gcc

[Alexander Fedotov <alfedotov at gmail dot com>]

Sure, I can check fix on my side.

Other way is to fix original issue from where this workaround comes
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14557. But seems nobody cares
it.

Alex

On Wed, 24 Jan 2018 at 20:46, Andre Vieira (lists) <
Andre.SimoesDiasVieira@arm.com> wrote:

> Sorry for my other email not replying to this, when I started writing it
> I hadn't seen your email yet.
>
> Anyhow, I suggested a change to your patch there at the end, if you
> could give that a try to see if it works for you too, then we could (at
> least for now) maybe get away with it.
>
> Cheers,
> Andre
>
> On 24/01/18 16:02, Alexander Fedotov wrote:
> > Hello Andre
> > Yes indeed this fix unfortunately broke an ARM port. I have no idea
> > why this builtins doesn't work on gcc for arm. Best way I believe
> > right now is to revert this commit.
> >
> > Alex
> >
> > On Tue, Jan 23, 2018 at 5:04 PM, Andre Vieira (lists)
> > <Andre.SimoesDiasVieira@arm.com> wrote:
> >> Hi Alexander,
> >>
> >> This patch is causing our arm-none-eabi-gcc newlib-nano builds to fail.
> >>
> >> It seems the _Generic isn't picking up the right type when ap is of type
> >> va_list. We get the following error:
> >> newlib/libc/stdio/nano-vfscanf.c:430:2: error: cannot convert to a
> >> pointer type
> >> ret = _scanf_chars (rptr, &scan_data, fp, va_ptr(ap));
> >> ^~~
> >> newlib/libc/stdio/nano-vfscanf.c:432:2: error: cannot convert to a
> >> pointer type
> >> ret = _scanf_i (rptr, &scan_data, fp, va_ptr(ap));
> >> ^~~
> >> newlib/libc/stdio/nano-vfscanf.c:435:2: error: cannot convert to a
> >> pointer type
> >> ret = _scanf_float (rptr, &scan_data, fp, va_ptr(ap));
> >>
> >>
> >> A reduced test-case, see:
> >>
> >> #include <stdio.h>
> >> extern void bar(va_list *ap);
> >> void foo(va_list ap) {
> >>     bar(_Generic(&(ap), va_list *: &(ap), default: (va_list *)(ap)));
> >> }
> >>
> >> Note that va_list for our toolchain is defined as gcc's
> __builtin_va_list.
> >>
> >> I have tried your other definitions of va_ptr too and none of them seem
> >> to work. How do you suggest we proceed?
> >>
> >> Cheers,
> >> Andre
> >>
> >>
> >>
> >> On 08/01/18 10:07, Corinna Vinschen wrote:
> >>> On Dec 25 16:39, Alexander Fedotov wrote:
> >>>> Hi
> >>>>
> >>>> I'm experienced a strange printf() for float variables behaviour with
> >>>> Nano version while regular is fine. It just prins out a garbage (even
> >>>> with enabled -u _printf_float). After some digging I've managed to
> >>>> track down issue until this line:
> >>>>
> >>>> n = _printf_float (data, &prt_data, fp, pfunc, &ap);
> >>>>
> >>>>
> >>>> Moreover there are number of warnings also in build log:
> >>>>
> >>>> src_newlib/newlib/libc/stdio/nano-vfprintf.c -o lib_a-nano-svfprintf.o
> >>>> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf.c: In
> >>>> function '_svfprintf_r':
> >>>> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf.c:645:55:
> >>>> warning: passing argument 5 of '_printf_float' from incompatible
> >>>> pointer type
> >>>>         n = _printf_float (data, &prt_data, fp, pfunc, &ap);
> >>>>
>   ^
> >>>> In file included from
> >>>> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf.c:169:0:
> >>>>
> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf_local.h:228:1:
> >>>> note: expected 'struct __va_list_tag (*)[1]' but argument is of type
> >>>> 'struct __va_list_tag **'
> >>>>  _printf_float (struct _reent *data,
> >>>>  ^
> >>>> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf.c:650:45:
> >>>> warning: passing argument 5 of '_printf_i' from incompatible pointer
> >>>> type
> >>>>   n = _printf_i (data, &prt_data, fp, pfunc, &ap);
> >>>>                                                             ^
> >>>> In file included from
> >>>> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf.c:169:0:
> >>>>
> ../../../../../../src_newlib/newlib/libc/stdio/nano-vfprintf_local.h:221:1:
> >>>> note: expected 'struct __va_list_tag (*)[1]' but argument is of type
> >>>> 'struct __va_list_tag **'
> >>>>  _printf_i (struct _reent *data, struct _prt_data_t *pdata, FILE *fp,
> >>>>
> >>>>
> >>>> It looks like nano written without taking in mind such targets. Here I
> >>>> found workaround https://gcc.gnu.org/bugzilla/show_bug.cgi?id=14557
> >>>> that's working.
> >>>>
> >>>> I'm attaching a patch.
> >>>>
> >>>> Alex
> >>>
> >>> Pushed.
> >>>
> >>>
> >>> Thanks,
> >>> Corinna
> >>>
> >>
> >
> >
> >
>
> --
Best regards,
AF