[gnome-desktop/ebassi/update-for-gtk4: 20/22] build: Allow disabling the legacy libgnome-desktop-3.0

[Emmanuele Bassi <ebassi src gnome org>]

commit 3fedfab62f91b144c295b028ab47281b73a59cda
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Nov 9 15:52:12 2021 +0000

    build: Allow disabling the legacy libgnome-desktop-3.0
    
    At some point, we're going to build only the 4.0 libraries except on
    older versions of GNOME.

 libgnome-desktop/meson.build | 236 ++++++++++++++++++++++---------------------
 meson.build                  |   2 +-
 meson_options.txt            |   4 +
 tests/meson.build            |  20 ++--
 4 files changed, 137 insertions(+), 125 deletions(-)
---
diff --git a/libgnome-desktop/meson.build b/libgnome-desktop/meson.build
index cb0eff21..f2420120 100644
--- a/libgnome-desktop/meson.build
+++ b/libgnome-desktop/meson.build
@@ -156,131 +156,133 @@ if gtk4_dep.found()
 endif
 
 ### Legacy ###
-introspection_sources = [
-  'gnome-desktop-thumbnail.c',
-  'gnome-bg.c',
-  'gnome-bg-slide-show.c',
-  'gnome-bg-crossfade.c',
-  'gnome-rr.c',
-  'gnome-rr-config.c',
-  'gnome-rr-output-info.c',
-  'gnome-systemd.c',
-  'gnome-pnp-ids.c',
-  'gnome-wall-clock.c',
-  'gnome-xkb-info.c',
-  'gnome-idle-monitor.c',
-  'gnome-languages.c',
-]
+if get_option('legacy_library')
+  introspection_sources = [
+    'gnome-desktop-thumbnail.c',
+    'gnome-bg.c',
+    'gnome-bg-slide-show.c',
+    'gnome-bg-crossfade.c',
+    'gnome-rr.c',
+    'gnome-rr-config.c',
+    'gnome-rr-output-info.c',
+    'gnome-systemd.c',
+    'gnome-pnp-ids.c',
+    'gnome-wall-clock.c',
+    'gnome-xkb-info.c',
+    'gnome-idle-monitor.c',
+    'gnome-languages.c',
+  ]
 
-libgnome_desktop_sources = [
-  introspection_sources,
-  dbus_xrandr_built_sources,
-  dbus_idle_built_sources,
-  'gnome-datetime-source.c',
-  'gnome-desktop-thumbnail-script.c',
-  'gnome-gettext-portable.c',
-]
+  libgnome_desktop_sources = [
+    introspection_sources,
+    dbus_xrandr_built_sources,
+    dbus_idle_built_sources,
+    'gnome-datetime-source.c',
+    'gnome-desktop-thumbnail-script.c',
+    'gnome-gettext-portable.c',
+  ]
 
-libgnome_desktop_headers = [
-  'gnome-bg.h',
-  'gnome-bg-crossfade.h',
-  'gnome-bg-slide-show.h',
-  'gnome-desktop-thumbnail.h',
-  'gnome-rr.h',
-  'gnome-rr-config.h',
-  'gnome-systemd.h',
-  'gnome-pnp-ids.h',
-  'gnome-wall-clock.h',
-  'gnome-xkb-info.h',
-  'gnome-idle-monitor.h',
-  'gnome-languages.h',
-]
+  libgnome_desktop_headers = [
+    'gnome-bg.h',
+    'gnome-bg-crossfade.h',
+    'gnome-bg-slide-show.h',
+    'gnome-desktop-thumbnail.h',
+    'gnome-rr.h',
+    'gnome-rr-config.h',
+    'gnome-systemd.h',
+    'gnome-pnp-ids.h',
+    'gnome-wall-clock.h',
+    'gnome-xkb-info.h',
+    'gnome-idle-monitor.h',
+    'gnome-languages.h',
+  ]
 
-install_headers(libgnome_desktop_headers,
-  subdir: 'gnome-desktop-3.0/libgnome-desktop'
-)
+  install_headers(libgnome_desktop_headers,
+    subdir: 'gnome-desktop-3.0/libgnome-desktop'
+  )
 
-gnome_desktop_deps = [
-  gdk_pixbuf_dep,
-  gtk3_dep,
-  glib_dep,
-  gio_dep,
-  gio_unix_dep,
-  libsystemd_dep,
-  schemas_dep,
-  xkb_config_dep,
-  xkbregistry_dep,
-  iso_codes_dep,
-  udev_dep,
-  seccomp_dep
-]
+  gnome_desktop_deps = [
+    gdk_pixbuf_dep,
+    gtk3_dep,
+    glib_dep,
+    gio_dep,
+    gio_unix_dep,
+    libsystemd_dep,
+    schemas_dep,
+    xkb_config_dep,
+    xkbregistry_dep,
+    iso_codes_dep,
+    udev_dep,
+    seccomp_dep
+  ]
 
-compat_ldflags = []
-compat_symbol_map = '-Wl,--version-script=@0@'.format(meson.current_source_dir() / 'symbol.map')
-if cc.has_link_argument(compat_symbol_map)
-  compat_ldflags += compat_symbol_map
-endif
+  compat_ldflags = []
+  compat_symbol_map = '-Wl,--version-script=@0@'.format(meson.current_source_dir() / 'symbol.map')
+  if cc.has_link_argument(compat_symbol_map)
+    compat_ldflags += compat_symbol_map
+  endif
 
-libgnome_desktop = library('gnome-desktop-3',
-  libgnome_desktop_sources,
-  dependencies: [gnome_desktop_deps, m_dep, rt_dep],
-  soversion: compat_soversion,
-  version: compat_libversion,
-  c_args: libargs,
-  link_args: compat_ldflags,
-  install: true,
-  include_directories: [
-    include_directories('.'),
-    include_directories('..'),
-  ],
-)
+  libgnome_desktop = library('gnome-desktop-3',
+    libgnome_desktop_sources,
+    dependencies: [gnome_desktop_deps, m_dep, rt_dep],
+    soversion: compat_soversion,
+    version: compat_libversion,
+    c_args: libargs,
+    link_args: compat_ldflags,
+    install: true,
+    include_directories: [
+      include_directories('.'),
+      include_directories('..'),
+    ],
+  )
 
-libgnome_desktop_dep = declare_dependency(
-  dependencies: gnome_desktop_deps,
-  link_with: libgnome_desktop,
-  include_directories: [
-    include_directories('.'),
-    include_directories('..'),
-  ],
-)
+  libgnome_desktop_dep = declare_dependency(
+    dependencies: gnome_desktop_deps,
+    link_with: libgnome_desktop,
+    include_directories: [
+      include_directories('.'),
+      include_directories('..'),
+    ],
+  )
 
-gnome.generate_gir(libgnome_desktop,
-  sources: introspection_sources + libgnome_desktop_headers,
-  export_packages: 'gnome-desktop-3.0',
-  namespace: 'GnomeDesktop',
-  nsversion: '3.0',
-  includes: ['GObject-2.0', 'Gtk-3.0', 'GDesktopEnums-3.0'],
-  extra_args: ['-DGNOME_DESKTOP_USE_UNSTABLE_API', '--quiet', '--warn-all'],
-  identifier_prefix: 'Gnome',
-  symbol_prefix: 'gnome',
-  install: true
-)
+  gnome.generate_gir(libgnome_desktop,
+    sources: introspection_sources + libgnome_desktop_headers,
+    export_packages: 'gnome-desktop-3.0',
+    namespace: 'GnomeDesktop',
+    nsversion: '3.0',
+    includes: ['GObject-2.0', 'Gtk-3.0', 'GDesktopEnums-3.0'],
+    extra_args: ['-DGNOME_DESKTOP_USE_UNSTABLE_API', '--quiet', '--warn-all'],
+    identifier_prefix: 'Gnome',
+    symbol_prefix: 'gnome',
+    install: true
+  )
 
-pkg.generate(
-  libraries: libgnome_desktop,
-  requires: ['gtk+-3.0', 'gsettings-desktop-schemas'],
-  version: meson.project_version(),
-  name: 'gnome-desktop-3.0',
-  filebase: 'gnome-desktop-3.0',
-  description: 'Utility library for loading .desktop files',
-  subdirs: 'gnome-desktop-3.0'
-)
+  pkg.generate(
+    libraries: libgnome_desktop,
+    requires: ['gtk+-3.0', 'gsettings-desktop-schemas'],
+    version: meson.project_version(),
+    name: 'gnome-desktop-3.0',
+    filebase: 'gnome-desktop-3.0',
+    description: 'Utility library for loading .desktop files',
+    subdirs: 'gnome-desktop-3.0'
+  )
 
-### Tests
-test_programs = [
-  'gnome-rr-debug',
-  'test-xkb-info',
-  'test-pnp-ids',
-  'test-wall-clock',
-  'test-desktop-thumbnail',
-  'test-idle-monitor',
-  'test-languages'
-]
+  ### Tests
+  test_programs = [
+    'gnome-rr-debug',
+    'test-xkb-info',
+    'test-pnp-ids',
+    'test-wall-clock',
+    'test-desktop-thumbnail',
+    'test-idle-monitor',
+    'test-languages'
+  ]
 
-foreach program: test_programs
-  executable(program, program + '.c',
-    dependencies: libgnome_desktop_dep,
-    install: get_option('debug_tools'),
-    install_dir: libexecdir / 'gnome-desktop-debug',
-  )
-endforeach
+  foreach program: test_programs
+    executable(program, program + '.c',
+      dependencies: libgnome_desktop_dep,
+      install: get_option('debug_tools'),
+      install_dir: libexecdir / 'gnome-desktop-debug',
+    )
+  endforeach
+endif
diff --git a/meson.build b/meson.build
index 68613093..ba9a149b 100644
--- a/meson.build
+++ b/meson.build
@@ -48,7 +48,7 @@ test_execdir = libexecdir / 'installed-tests' / meson.project_name()
 versiondir = datadir / 'gnome'
 
 gdk_pixbuf_dep = dependency('gdk-pixbuf-2.0', version: gdk_pixbuf_req)
-gtk3_dep = dependency('gtk+-3.0', version: gtk3_req)
+gtk3_dep = dependency('gtk+-3.0', version: gtk3_req, required: get_option('legacy_library'))
 gtk4_dep = dependency('gtk4', version: gtk4_req, required: get_option('build_gtk4'))
 glib_dep = dependency('glib-2.0', version: glib_req)
 gio_dep = dependency('gio-2.0', version: glib_req)
diff --git a/meson_options.txt b/meson_options.txt
index 9fe2d7bd..e17e7330 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -36,3 +36,7 @@ option('installed_tests',
 option('build_gtk4',
   type: 'boolean', value: true, description: 'Enable GTK4 libraries'
 )
+
+option('legacy_library',
+  type: 'boolean', value: true, description: 'Build the legacy libgnome-desktop-3.0'
+)
diff --git a/tests/meson.build b/tests/meson.build
index 3b4c0666..cafb0978 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -11,15 +11,21 @@ test_env = [
   'G_ENABLE_DIAGNOSTICS=0'
 ]
 
-test_programs = [
-  'bg-slide-show',
-  'wall-clock',
-  'wallclock-reftest',
-  'languages'
-]
-
+test_programs = []
 test_metas = []
 
+# XXX: The current batch of tests relies on the legacy library
+if get_option('legacy_library')
+  test_programs += [
+    'bg-slide-show',
+    'wall-clock',
+    'wallclock-reftest',
+    'languages'
+  ]
+
+  test_metas += []
+endif
+
 foreach program: test_programs
   exe = executable(program, program + '.c',
     dependencies: libgnome_desktop_dep,