Re: install/48303: Linux cross build fails on ppc

[Justin Cormack <justin%specialbusservice.com@localhost>]

On Mon, Oct 28, 2013 at 1:00 PM, Alan Barrett <apb%cequrux.com@localhost> wrote:
> The following reply was made to PR toolchain/48303; it has been noted by 
> GNATS.
>
> From: Alan Barrett <apb%cequrux.com@localhost>
> To: gnats-bugs%netbsd.org@localhost
> Cc:
> Subject: Re: install/48303: Linux cross build fails on ppc
> Date: Mon, 28 Oct 2013 14:57:38 +0200
>
>  On Mon, 28 Oct 2013, Justin Cormack wrote:
>  >I looked at where this was being redefined and it is in compat_defs.h
>  >and the following patch fixes this issue, which makes it somewhat
>  >simpler than I thought to fix. The only question is whether undefining
>  >__unused is necessary on some other platform, in which case the
>  >#define __unused could be wrapped eg in #ifndef __linux__ which should
>  >be safe.
>
>  Is the Linux use of "__unused" as a struct member name something new?

It is generally only found in non-x86 architectures, although it is
also in some versions of struct stat on x86.

>  Did you test a complete build with your patch?  The reason for the
>  "#define __unused", which has been in compat_defs.h since 2006-10-12, is
>  to deal with code that uses __unused in the NetBSD way, like
>
>         sometype varname __unused;
>
>  and if __unused is not defined then such code would cause a syntax
>  error.  There seems to be such code in src/usr.sbin/makefs, which would
>  be built from src/tools/makefs.  There might also be more uses of
>  __unused in the tools build.

Yes, apologies this patch will not work, the build eventually fails.

I have filed a patch against glibc
https://sourceware.org/ml/libc-alpha/2013-10/msg00870.html not sure if
they will respond. It will still take a few years to filter to end
user machines, so perhaps at least a note on the README in the compat
directory could be helpful if there is really no way to fix this.

Justin