From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [PATCH Remus v2 02/10] tools/libxc: introduce
 setup() and cleanup() on save
Date: Mon, 11 May 2015 12:49:33 +0100
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On Mon, 2015-05-11 at 12:47 +0100, Ian Campbell wrote:
> > >> Actually this is another trick that I need to deal with those
> > >> hypercall macros.
> > >> DECLARE_HYPERCALL_BUFFER_SHADOW will define a user pointer "dirty_bitmap"
> > >> and a shadow buffer, although xc_hypercall_buffer_free_pages takes
> > >> "dirty_bitmap" as an augument, but it is also a MACRO, without
> > >> "if ( dirty_bitmap )", the compiler will report "dirty_bitmap" unused
> > >> error...
> > >
> > > Ah, in which case you would be better using
> > > xc__hypercall_buffer_free_pages() and not creating the local shadow in
> > > the first place.
> > 
> > I thought we'd better use those MACROs which described in the comments...
> > If it is OK to use xc__hypercall_buffer_free_pages(), I will fix it in
> > the next version.
> 
> If anything I think I'd prefer for the if to move inside the
> xc_hypercall_buffer_free_pages macro.

Or if you want to use the "raw" xc__hypercall_buffer variant you should
be consistent and do the same on allocation.

Ian.