Re: [PATCH] stubdom: foreignmemory: Fix build after 0dbb4be739c5

[Julien Grall <julien@xxxxxxx>]

On 13/07/2021 10:27, Juergen Gross wrote:
> On 13.07.21 11:20, Julien Grall wrote:
> > From: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > Commit 0dbb4be739c5 add the inclusion of xenctrl.h from private.h and
> > wreck the build in an interesting way:
> >
> > In file included from xen/stubdom/include/xen/domctl.h:39:0,
> >                   from xen/tools/include/xenctrl.h:36,
> >                   from private.h:4,
> >                   from minios.c:29:
> > xen/include/public/memory.h:407:5: error: expected 
> > specifier-qualifier-list before ‘XEN_GUEST_HANDLE_64’
> >       XEN_GUEST_HANDLE_64(const_uint8) buffer;
> >       ^~~~~~~~~~~~~~~~~~~
> >
> > This is happening because xenctrl.h defines __XEN_TOOLS__ and therefore
> > the public headers will start to expose the non-stable ABI. However,
> > xen.h has already been included by a mini-OS header before hand. So
> > there is a mismatch in the way the headers are included.
> >
> > For now solve it in a very simple (and gross) way by including
> > xenctrl.h before the mini-os headers.
> >
> > Fixes: 0dbb4be739c5 ("tools/libs/foreignmemory: Fix PAGE_SIZE 
> > redefinition error")
> > Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
> >
> > ---
> >
> > Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> >
> > I couldn't find a better way with would not result to revert the patch
> > (and break build on some system) or involve a longer rework of the
> > headers.
> Just adding a "#define __XEN_TOOLS__" before the #include statements
> doesn't work?
It works but if someone decides to the rework the header and drop 
__XEN_TOOLS__ we would still define in minios.c (we technically don't 
need it). So I find the solution a lot worse than what I wrote.
> > ---
> >   tools/libs/foreignmemory/minios.c | 8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/tools/libs/foreignmemory/minios.c 
> > b/tools/libs/foreignmemory/minios.c
> > index c5453736d598..d7b3f0e1c823 100644
> > --- a/tools/libs/foreignmemory/minios.c
> > +++ b/tools/libs/foreignmemory/minios.c
> > @@ -17,6 +17,14 @@
> >    * Copyright 2007-2008 Samuel Thibault <samuel.thibault@xxxxxxxxxxxxx>.
> >    */
> > +/*
> > + * xenctlr.h currently defines __XEN_TOOLS__ which affects what is
> Typo, should be xenctrl.h
I will fix it.

--
Julien Grall