Re: [PATCH] libgloss: arm: break newlib dependency

Mike Frysinger <[email protected]> Thu, 22 Dec 2022 17:03:40 -0500
Newsgroups	gmane.comp.lib.newlib
Message-ID	<Y6TUPP6M1h5Aopp2@vapier>
On 21 Dec 2022 09:24, Corinna Vinschen wrote:
> On Dec 20 20:47, Mike Frysinger wrote:
> > On 19 Dec 2022 10:08, Richard Earnshaw wrote:
> > > On 14/12/2022 09:13, Mike Frysinger wrote:
> > > > The libgloss port has been reaching back into newlib internals for a
> > > > single header whose contents have been frozen for almost a decade.
> > > > To break this backwards libgloss->newlib dependency, duplicate that
> > > > header here so we can keep libgloss independent as it's meant to be.
> > > 
> > > This isn't really 'newlib internals', it's a header file that tries to 
> > > provide ACLE[1] compatibility for older versions of GCC that lacked such 
> > > support.  Having two copies of this is a maintenance burden, so I'm not 
> > > entirely sure this is a great thing to do, even if the copies are 
> > > supposed to be identical.
> > 
> > newlib already has 2 itself.  so this will be a 3rd.  i don't disagree with
> > the maintenance concern, but the fact the file hasn't changed in a decade,
> > and seems unlikely to ever change, makes me not worry about it.
> > 
> > > If we can agree on a common location in the source tree that both newlib 
> > > and libgloss can pull this from, then I'm happy to move it if that would 
> > > make you happier.
> > 
> > libgloss is supposed to be C library agnostic.  the C library (newlib) itself
> > relies on the output of libgloss (e.g. the crt and low level syscalls).  since
> > there is no other tree/project in play that i'm aware of, that means there are
> > really only three options:
> > * have the compiler provide it
> > * have libgloss provide it (and newlib uses that)
> > * duplicate the header
> > 
> > i know the libgloss/newlib separation is still pretty unclean due to the two
> > projects historically being one (i.e. everything in newlib), but i don't think
> > that's a good reason to keep it messy with libgloss depending on newlib.
> 
> Why not just <toplevel>/include then?  It already contains target-specific
> stuff in the opcodes subdir, or the xtensa headers.  Having to share them
> between newlib and libgloss should be reason enough to move the file there.

the file is currently installed under machine/.  none of the installed headers
use it though, so maybe it doesn't really need to be installed.  if that's the
case, moving it into the top-level include/ would work.
-mike
signature.asc (application/pgp-signature, 833 B)