Re: [Qemu-devel] OpenBSD build fixes

[Stuart Brady <sdbrady@ntlworld.com>]

On Mon, Oct 05, 2009 at 10:23:35PM +0100, Laurence Tratt wrote:

> In an ideal world, I would love qemu to work out of the box on OpenBSD. Both
> the things I'm referring to relate to things that appear simply to be
> missing from OpenBSD - for example ONLY_IF_RO prevents x86_64.ld from
> compiling, and has to be removed. While I'd be happy to see those removed
> from the tree, I assume they have semantic meaning for other platforms, and
> that's something we have to live without. As this implies, this stuff is a
> little outside my normal experience, but given that no-one else more
> qualified has ported a recent version of qemu to OpenBSD [/amd64 in
> particular], I guess it'll have to do!

I *think* it should be safe to drop the lines using ONLY_IF_RO, provided
that you also make the ONLY_IF_RW lines be unconditional.

The proper fix might be to pass the script through a preprocessor
(perhaps the C preprocessor, with a set of #ifdefs) on affected hosts.

Note that ia64, m68k and s390 also mark .eh_frame and .gcc_except_table
with KEEP { ... }, but place them in the data segment (i.e. without
using ONLY_IF_RO and ONLY_IF_RW).  I expect that you're only really
concerned with x86_64 for the time being, but note that hppa, mips, ppc
and ppc64 also use ONLY_IF_RO and ONLY_IF_RW.

I'd certainly argue that it's best to post any OpenBSD-specific patches
to the list with [RFC] in the subject line, so that anyone who might
know a better fix for a specific issue can offer their suggestions.
It's sometimes the case that a fix is also relevant to one of the other
Un*xes or Windows, so I think it's well worth keeping the list informed
of any issues that you find.

Also, I feel that it's worth having the current code in Git compile and
run under OpenBSD -- I can't see any reason to treat OpenBSD as a second
class citizen, nor any other significant OS.

Cheers,
-- 
Stuart Brady