Re: Upstreaming the glibc Hurd port

[Joseph Myers]

On Wed, 24 Jan 2018, Samuel Thibault wrote:

> Hello,
> 
> Joseph Myers, on ven. 19 janv. 2018 17:23:29 +0000, wrote:
> > Could Hurd people review how this handles building for Hurd,
> 
> Yes, it looks good.

Thanks, I've committed it to master.

> > and indicate whether the above errors indicate problems with these
> > changes, or simply incompleteness of the build support on the
> > sthibaul/hurd-builds branch at present?
> 
> They are not related to the changes.  I have pushed fix updates against
> them.

Now I see errors about missing libc-lockP.h, and "implicit declaration of 
function '__spin_lock_solid'", and the discarded qualifiers errors you 
note below.

> There is just one missing thing: mig prototypes etc. are not perfect,
> and we thus have some nasty warnings about void * vs const void *. We'd
> have to use
> 
>          if self.os == 'gnu':
>              cfg_cmd += ['MIG=%s' % self.tool_name('mig')]
> +            cfg_cmd += ['--disable-werror']
> 
> for now until we fix that.

A properly upstreamed port should not need --disable-werror.  If 
workarounds are needed until there's a fixed mig release (or whatever), 
they could take the form of explicit casts, or CFLAGS-<file> += 
-Wno-error=discarded-qualifiers - disabling a particular warning being an 
error in a particular file is much better than globally disabling all 
warnings as errors.  (Strictly -Wno-error=discarded-qualifiers shouldn't 
be used unconditionally since that warning option is new in GCC 5 and 
glibc supports building with GCC 4.9, but in the current state of the Hurd 
port I think we can ignore that in Hurd-specific Makefiles.)

-- 
Joseph S. Myers
joseph@codesourcery.com