Re: [PATCH v2] gtk: disable GTK Clipboard with a new meson option

[Jim Fehlig]

On 11/21/22 06:55, Claudio Fontana wrote:
> The GTK Clipboard implementation may cause guest hangs.
>
> Therefore implement new configure switch: --enable-gtk-clipboard,
>
> as a meson option disabled by default, which warns in the help
> text about the experimental nature of the feature.
> Regenerate the meson build options to include it.
>
> The initialization of the clipboard is gtk.c, as well as the
> compilation of gtk-clipboard.c are now conditional on this new
> option to be set.
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1150
> Signed-off-by: Claudio Fontana <cfontana@suse.de>
> Acked-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>   meson.build                   | 5 +++++
>   meson_options.txt             | 7 +++++++
>   scripts/meson-buildoptions.sh | 3 +++
>   ui/gtk.c                      | 2 ++
>   ui/meson.build                | 5 ++++-
>   5 files changed, 21 insertions(+), 1 deletion(-)

Compile-tested only. Oh, and ensured './configure --help' contained your text 
:-).

Reviewed-by: Jim Fehlig <jfehlig@suse.com>

> v1 -> v2:
>
> * fixed a too long line in scripts/meson-buildoptions.sh (checkpatch)
>
> * meson.build: set have_gtk_clipboard variable once, avoid duplication (Jim)
>
> * mention the warnings about experimental nature of the feature in commit
>
> diff --git a/meson.build b/meson.build
> index cf3e517e56..5c6b5a1c75 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1246,6 +1246,8 @@ endif
>   gtk = not_found
>   gtkx11 = not_found
>   vte = not_found
> +have_gtk_clipboard = get_option('gtk_clipboard').enabled()
> +
>   if not get_option('gtk').auto() or have_system
>     gtk = dependency('gtk+-3.0', version: '>=3.22.0',
>                      method: 'pkg-config',
> @@ -1264,6 +1266,8 @@ if not get_option('gtk').auto() or have_system
>                          required: get_option('vte'),
>                          kwargs: static_kwargs)
>       endif
> +  elif have_gtk_clipboard
> +    error('GTK clipboard requested, but GTK not found')
>     endif
>   endif
>   
> @@ -1842,6 +1846,7 @@ if glusterfs.found()
>   endif
>   config_host_data.set('CONFIG_GTK', gtk.found())
>   config_host_data.set('CONFIG_VTE', vte.found())
> +config_host_data.set('CONFIG_GTK_CLIPBOARD', have_gtk_clipboard)
>   config_host_data.set('CONFIG_LIBATTR', have_old_libattr)
>   config_host_data.set('CONFIG_LIBCAP_NG', libcap_ng.found())
>   config_host_data.set('CONFIG_EBPF', libbpf.found())
> diff --git a/meson_options.txt b/meson_options.txt
> index 66128178bf..4b749ca549 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -219,6 +219,13 @@ option('vnc_sasl', type : 'feature', value : 'auto',
>          description: 'SASL authentication for VNC server')
>   option('vte', type : 'feature', value : 'auto',
>          description: 'vte support for the gtk UI')
> +
> +# GTK Clipboard implementation is disabled by default, since it may cause hangs
> +# of the guest VCPUs. See gitlab issue 1150:
> +# https://gitlab.com/qemu-project/qemu/-/issues/1150
> +
> +option('gtk_clipboard', type: 'feature', value : 'disabled',
> +       description: 'clipboard support for the gtk UI (EXPERIMENTAL, MAY 
> HANG)')
>   option('xkbcommon', type : 'feature', value : 'auto',
>          description: 'xkbcommon support')
>   option('zstd', type : 'feature', value : 'auto',
> diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
> index 2cb0de5601..aa6e30ea91 100644
> --- a/scripts/meson-buildoptions.sh
> +++ b/scripts/meson-buildoptions.sh
> @@ -93,6 +93,7 @@ meson_options_help() {
>     printf "%s\n" '  glusterfs       Glusterfs block device driver'
>     printf "%s\n" '  gnutls          GNUTLS cryptography support'
>     printf "%s\n" '  gtk             GTK+ user interface'
> +  printf "%s\n" '  gtk-clipboard   clipboard support for GTK (EXPERIMENTAL, 
> MAY HANG)'
>     printf "%s\n" '  guest-agent     Build QEMU Guest Agent'
>     printf "%s\n" '  guest-agent-msi Build MSI package for the QEMU Guest Agent'
>     printf "%s\n" '  hax             HAX acceleration support'
> @@ -274,6 +275,8 @@ _meson_option_parse() {
>       --disable-gprof) printf "%s" -Dgprof=false ;;
>       --enable-gtk) printf "%s" -Dgtk=enabled ;;
>       --disable-gtk) printf "%s" -Dgtk=disabled ;;
> +    --enable-gtk-clipboard) printf "%s" -Dgtk_clipboard=enabled ;;
> +    --disable-gtk-clipboard) printf "%s" -Dgtk_clipboard=disabled ;;
>       --enable-guest-agent) printf "%s" -Dguest_agent=enabled ;;
>       --disable-guest-agent) printf "%s" -Dguest_agent=disabled ;;
>       --enable-guest-agent-msi) printf "%s" -Dguest_agent_msi=enabled ;;
> diff --git a/ui/gtk.c b/ui/gtk.c
> index 7ec21f7798..4817623c8f 100644
> --- a/ui/gtk.c
> +++ b/ui/gtk.c
> @@ -2403,7 +2403,9 @@ static void gtk_display_init(DisplayState *ds, 
> DisplayOptions *opts)
>           opts->u.gtk.show_tabs) {
>           gtk_menu_item_activate(GTK_MENU_ITEM(s->show_tabs_item));
>       }
> +#ifdef CONFIG_GTK_CLIPBOARD
>       gd_clipboard_init(s);
> +#endif /* CONFIG_GTK_CLIPBOARD */
>   }
>   
>   static void early_gtk_display_init(DisplayOptions *opts)
> diff --git a/ui/meson.build b/ui/meson.build
> index ec13949776..c1b137bf33 100644
> --- a/ui/meson.build
> +++ b/ui/meson.build
> @@ -97,7 +97,10 @@ if gtk.found()
>     softmmu_ss.add(when: 'CONFIG_WIN32', if_true: files('win32-kbd-hook.c'))
>   
>     gtk_ss = ss.source_set()
> -  gtk_ss.add(gtk, vte, pixman, files('gtk.c', 'gtk-clipboard.c'))
> +  gtk_ss.add(gtk, vte, pixman, files('gtk.c'))
> +  if have_gtk_clipboard
> +    gtk_ss.add(files('gtk-clipboard.c'))
> +  endif
>     gtk_ss.add(when: x11, if_true: files('x_keymap.c'))
>     gtk_ss.add(when: opengl, if_true: files('gtk-gl-area.c'))
>     gtk_ss.add(when: [x11, opengl], if_true: files('gtk-egl.c'))