RE: [RFC v2 2/2] ui: Add a plain Wayland backend for Qemu UI

["Kasireddy, Vivek" <vivek.kasireddy@intel.com>]

Hi Daniel,
 
> On Mon, Sep 13, 2021 at 03:20:36PM -0700, Vivek Kasireddy wrote:
> > Cc: Gerd Hoffmann <kraxel@redhat.com>
> > Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
> > ---
> >  configure         |   8 +-
> >  meson.build       |  33 +++
> >  meson_options.txt |   2 +
> >  qapi/ui.json      |   3 +
> >  ui/meson.build    |  52 ++++
> >  ui/wayland.c      | 628 ++++++++++++++++++++++++++++++++++++++++++++++
> >  6 files changed, 725 insertions(+), 1 deletion(-)  create mode 100644
> > ui/wayland.c
> 
> 
> > diff --git a/ui/meson.build b/ui/meson.build index
> > a73beb0e54..86fc324c82 100644
> > --- a/ui/meson.build
> > +++ b/ui/meson.build
> > @@ -64,6 +64,58 @@ if config_host.has_key('CONFIG_OPENGL') and gbm.found()
> >    ui_modules += {'egl-headless' : egl_headless_ss}  endif
> >
> > +wayland_scanner = find_program('wayland-scanner') proto_sources = [
> > +  ['xdg-shell', 'stable', ],
> > +  ['fullscreen-shell', 'unstable', 'v1', ],
> > +  ['linux-dmabuf', 'unstable', 'v1', ], ] wayland_headers = []
> > +wayland_proto_sources = []
> > +
> > +if wayland.found()
> > +  foreach p: proto_sources
> > +    proto_name = p.get(0)
> > +    proto_stability = p.get(1)
> > +
> > +    if proto_stability == 'stable'
> > +      output_base = proto_name
> > +      input = files(join_paths(wlproto_dir,
> '@0@/@1@/@2@.xml'.format(proto_stability, proto_name, output_base)))
> > +    else
> > +      proto_version = p.get(2)
> > +      output_base = '@0@-@1@-@2@'.format(proto_name, proto_stability,
> proto_version)
> > +      input = files(join_paths(wlproto_dir,
> '@0@/@1@/@2@.xml'.format(proto_stability, proto_name, output_base)))
> > +    endif
> > +
> > +    wayland_headers += custom_target('@0@ client header'.format(output_base),
> > +      input: input,
> > +      output: '@0@-client-protocol.h'.format(output_base),
> > +      command: [
> > +        wayland_scanner,
> > +        'client-header',
> > +        '@INPUT@', '@OUTPUT@',
> > +      ], build_by_default: true
> > +    )
> > +
> > +    wayland_proto_sources += custom_target('@0@ source'.format(output_base),
> > +      input: input,
> > +      output: '@0@-protocol.c'.format(output_base),
> > +      command: [
> > +        wayland_scanner,
> > +        'private-code',
> > +        '@INPUT@', '@OUTPUT@',
> > +      ], build_by_default: true
> > +    )
> > +  endforeach
> > +endif
> > +
> > +if wayland.found()
> > +  wayland_ss = ss.source_set()
> > +  wayland_ss.add(when: wayland, if_true: files('wayland.c',
> > +'xdg-shell-protocol.c',
> > +'fullscreen-shell-unstable-v1-protocol.c','linux-dmabuf-unstable-v1-p
> > +rotocol.c'))
> > +  #wayland_ss.add(when: wayland, if_true: files('wayland.c'),
> > +[wayland_proto_sources])
> > +  ui_modules += {'wayland' : wayland_ss} endif
> 
> Configure fails on this
> 
>   Program wayland-scanner found: YES (/usr/bin/wayland-scanner)
> 
>   ../ui/meson.build:114:13: ERROR: File xdg-shell-protocol.c does not exist.
> 
> 
> the code a few lines above generates xdg-shell-protocol.c, but that isn't run until you type
> "make", so when meson is resolving the source files they don't exist.
> 
> The alternative line you have commented out looks more like what we would need, but it
> doesn't work either as its syntax is invalid.
[Kasireddy, Vivek] Right, the commented line is the one we'd need but despite exhaustively
trying various different combinations, I couldn't get Meson to include the auto-generated
protocol sources. If it is not too much trouble, could you please point me to an example
where this is done elsewhere in Qemu source that I can look at?

> 
> How did you actually compile this series ?
[Kasireddy, Vivek] Oh, as a workaround, I just manually added the protocol sources. I am
sorry I did not realize that this code would be compiled/tested; I mainly posted these
RFC/WIP patches to provide additional context to the discussion associated with the DRM/
Virtio-gpu kernel patches.

Thanks,
Vivek

> 
> 
> Regards,
> Daniel
> --
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