Re: [PATCH] Merge glibc ieee128 ldbl redirect support into cdefs.h

[Paul E Murphy]

On 1/4/21 12:27 PM, Bruno Haible wrote:
> Paul E Murphy wrote:
> > We ran into the following:
> >
> > In file included from
> > /home/tuliom/opt/at-next-15.0-0-alpha/include/stdio.h:871,
> >                    from ./stdio.h:43,
> >                    from
> > /home/tuliom/tmp/at-build-tray/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources
> > /gdb/gnulib/import/tempname.h:23,
> >                    from
> > /home/tuliom/tmp/at-build-tray/at15.0-0-alpha.redhat-8_ppc64le_ppc64le/sources
> > /gdb/gnulib/import/tempname.c:20:
> > /home/tuliom/opt/at-next-15.0-0-alpha/include/bits/stdio-ldbl.h: In
> > function ‘__LDBL_REDIR1_DECL’:
> > /home/tuliom/opt/at-next-15.0-0-alpha/include/bits/stdio-ldbl.h:36:1:
> > error: expected declaration specifiers before ‘__LDBL_REDIR1_DECL’
> >      36 | __LDBL_REDIR1_DECL (scanf, __isoc99_scanfieee128)
> >         | ^~~~~~~~~~~~~~~~~~
> >
> >
> > The missing macro is provided by glibc's cdefs.h.  Thus, the wrong
> > cdefs.h was picked up.
>
> The one from glibc is meant to be included when someone writes
>    #include <sys/cdefs.h>
>
> The one from Gnulib is meant to be included when someone writes
>    #include <cdefs.h>
> via
>    #include <libc-config.h>
>
> If the wrong one was picked up, it sounds you have too many -I options
> in your compilation commands.

Oops, the trace I posted wasn't complete.  Here it is in it's full form. 
 The gnulib headers are included as expected.

Note, this is building with -mabi=ieeelongdouble option, thus this 
requires both a sufficiently new gcc (8+) and glibc (2.23+).

In file included from 
/home/murp/opt/at-next-15.0-0-alpha/include/stdio.h:871,
                 from ./stdio.h:43,
                 from 
/home/murp/tmp/at-build-tray/at15.0-0-alpha.ubuntu-18_ppc64le_ppc64le/sources/gdb/gnulib/import/tempname.h:23,
                 from 
/home/murp/tmp/at-build-tray/at15.0-0-alpha.ubuntu-18_ppc64le_ppc64le/sources/gdb/gnulib/import/tempname.c:20:
/home/murp/opt/at-next-15.0-0-alpha/include/bits/stdio-ldbl.h: In 
function ‘__LDBL_REDIR1_DECL’:
/home/murp/opt/at-next-15.0-0-alpha/include/bits/stdio-ldbl.h:36:1: 
error: expected declaration specifiers before ‘__LDBL_REDIR1_DECL’
   36 | __LDBL_REDIR1_DECL (scanf, __isoc99_scanfieee128)
      | ^~~~~~~~~~~~~~~~~~
In file included from ./stdio.h:53,
                 from 
/home/murp/tmp/at-build-tray/at15.0-0-alpha.ubuntu-18_ppc64le_ppc64le/sources/gdb/gnulib/import/tempname.h:23,
                 from 
/home/murp/tmp/at-build-tray/at15.0-0-alpha.ubuntu-18_ppc64le_ppc64le/sources/gdb/gnulib/import/tempname.c:20: