widget-factory: Speed up build

Avoid serializing the gresource blob into a C string
and running gcc over it. Instead, use ld to put it
directly into an .o file and add it to the build.

The build system machinations here were copied from
gobject/tests/meson.build, and should ideally be part
of the meson gnome module.

diff --git a/demos/widget-factory/meson.build b/demos/widget-factory/meson.build
index 6b09db3e2bc968a915b90f75d715bd8fca6e6c31..27631115705f9b93690f30c0fd643b1d495292d5 100644 (file)
--- a/demos/widget-factory/meson.build
+++ b/demos/widget-factory/meson.build
@@ -1,9 +1,68 @@
 # demos/widget-factory
 
-widgetfactory_resources = gnome.compile_resources('widgetfactory_resources',
-  'widget-factory.gresource.xml',
-  source_dir: '.',
-)
+objcopy_supports_add_symbol = false
+objcopy = find_program('objcopy', required : false)
+if objcopy.found()
+  objcopy_supports_add_symbol = run_command(objcopy, '--help').stdout().contains('--add-symbol')
+endif
+
+ld = find_program('ld', required : false)
+
+if build_machine.system() == 'linux' and objcopy.found() and objcopy_supports_add_symbol and ld.found()
+  glib_compile_resources = find_program('glib-compile-resources')
+
+  # Create the resource blob
+  widgetfactory_gresource = custom_target('widgetfactory.gresource',
+      input : 'widget-factory.gresource.xml',
+      output : 'widgetfactory.gresource',
+      command : [glib_compile_resources,
+                 '--target=@OUTPUT@',
+                 '--sourcedir=' + meson.current_source_dir(),
+                 '--sourcedir=' + meson.current_build_dir(),
+                 '@INPUT@'])
+
+  # Create resource data file
+  widgetfactory_resources_c = custom_target('widgetfactory_resources.c',
+      input : 'widget-factory.gresource.xml',
+      output : 'widgetfactory_resources.c',
+      command : [glib_compile_resources,
+                 '--target=@OUTPUT@',
+                 '--sourcedir=' + meson.current_source_dir(),
+                 '--sourcedir=' + meson.current_build_dir(),
+                 '--generate-source',
+                 '--external-data',
+                 '--c-name', '_g_binary_widgetfactory',
+                 '@INPUT@'])
+
+  # Create object file containing resource data
+  widgetfactory_resources_binary = custom_target('widgetfactory_resources.o',
+      input : widgetfactory_gresource,
+      output : 'widgetfactory_resources.o',
+      command : [ld,
+                 '-r',
+                 '-b','binary',
+                 '@INPUT@',
+                 '-o','@OUTPUT@'])
+
+  # Rename symbol to match the one in the C file
+  widgetfactory_resources_o = custom_target('widgetfactory_resources2.o',
+    input : widgetfactory_resources_binary,
+    output : 'widgetfactory_resources2.o',
+    command : [objcopy,
+                 '--add-symbol','_g_binary_widgetfactory_resource_data=.data:0',
+                 '@INPUT@',
+                 '@OUTPUT@'])
+
+  widgetfactory_resources = [
+      widgetfactory_resources_c,
+      widgetfactory_resources_o,
+    ]
+else
+  widgetfactory_resources = gnome.compile_resources('widgetfactory_resources',
+    'widget-factory.gresource.xml',
+    source_dir: '.',
+  )
+endif
 
 executable('gtk4-widget-factory',
   sources: ['widget-factory.c', 'gtkloader.c', widgetfactory_resources],