From 802ad3920988d3d8104b9f438a820633a1ed76fd Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Thu, 30 Sep 2021 22:55:31 -0400
Subject: [PATCH] gtk: 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.
---
 gtk/meson.build | 85 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 74 insertions(+), 11 deletions(-)

diff --git a/gtk/meson.build b/gtk/meson.build
index bc097fdd6f..8907c1c6dd 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -863,17 +863,80 @@ if not fs.exists('theme/Default/Default-light.css')
   endif
 endif
 
-gtkresources = gnome.compile_resources('gtkresources',
-  gtk_gresources_xml,
-  dependencies: theme_deps,
-  source_dir: [
-    # List in order of preference
-    meson.current_build_dir(),
-    meson.current_source_dir(),
-  ],
-  c_name: '_gtk',
-  extra_args: '--manual-register',
-)
+
+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
+  gtk_gresource = custom_target('gtk.gresource',
+      input : gtk_gresources_xml,
+      depends : theme_deps,
+      output : 'gtk.gresource',
+      command : [glib_compile_resources,
+                 '--target=@OUTPUT@',
+                 '--sourcedir=' + meson.current_source_dir(),
+                 '--sourcedir=' + meson.current_build_dir(),
+                 '@INPUT@'])
+
+  # Create resource data file
+  gtk_resources_c = custom_target('gtk_resources.c',
+      input : gtk_gresources_xml,
+      depends : theme_deps,
+      output : 'gtk_resources.c',
+      command : [glib_compile_resources,
+                 '--target=@OUTPUT@',
+                 '--sourcedir=' + meson.current_source_dir(),
+                 '--sourcedir=' + meson.current_build_dir(),
+                 '--generate-source',
+                 '--external-data',
+                 '--c-name', '_gtk',
+                 '--manual-register',
+                 '@INPUT@'])
+
+  # Create object file containing resource data
+  gtk_resources_binary = custom_target('gtk_resources.o',
+      input : gtk_gresource,
+      output : 'gtk_resources.o',
+      command : [ld,
+                 '-r',
+                 '-b','binary',
+                 '@INPUT@',
+                 '-o','@OUTPUT@'])
+
+  # Rename symbol to match the one in the C file
+  gtk_resources_o = custom_target('gtk_resources2.o',
+    input : gtk_resources_binary,
+    output : 'gtk_resources2.o',
+    command : [objcopy,
+                 '--add-symbol','_gtk_resource_data=.data:0',
+                 '@INPUT@',
+                 '@OUTPUT@'])
+
+  gtkresources = [
+      gtk_resources_c,
+      gtk_resources_o,
+    ]
+else
+  gtkresources = gnome.compile_resources('gtkresources',
+    gtk_gresources_xml,
+    dependencies: theme_deps,
+    source_dir: [
+      # List in order of preference
+      meson.current_build_dir(),
+      meson.current_source_dir(),
+    ],
+    c_name: '_gtk',
+    extra_args: '--manual-register',
+  )
+endif
 
 foreach lang : [ 'de', 'fr', 'es', 'zh' ]
   conf = configuration_data()
-- 
2.30.2