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

Mike Frysinger <[email protected]> Tue, 20 Dec 2022 20:47:53 -0500

Newsgroups	gmane.comp.lib.newlib
Message-ID	<Y6JlydSTs3vWtnix@vapier>

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.
-mike

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