[gnome-settings-daemon] build: Apply a workaround for D-Bus code generation

[Bastien Nocera <hadess src gnome org>]

commit 5924d72931a030b24554116a48140a661a99652b
Author: Iñigo Martínez <inigomartinez gmail com>
Date:   Mon Feb 5 19:38:36 2018 +0100

    build: Apply a workaround for D-Bus code generation
    
    meson uses gdbus-codegen for D-Bus code generation. However, both
    files are generated implicitly, so meson is not able to know how
    many files are generated, so it does generate only one opaque
    target that represents the two files.
    
    A new script has been created only to call gdbus-codegen and
    simulate the generation of the source code and header as different
    targets.
    
    Please see:
      https://bugzilla.gnome.org/show_bug.cgi?id=791015
      https://github.com/mesonbuild/meson/pull/2930
    
    https://bugzilla.gnome.org/show_bug.cgi?id=793087

 gnome-settings-daemon/codegen.py  |   31 +++++++++++++++++++++++++++++++
 gnome-settings-daemon/meson.build |   28 ++++++++++++++++++++++++++--
 2 files changed, 57 insertions(+), 2 deletions(-)
---
diff --git a/gnome-settings-daemon/codegen.py b/gnome-settings-daemon/codegen.py
new file mode 100644
index 0000000..eb0b0ce
--- /dev/null
+++ b/gnome-settings-daemon/codegen.py
@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+'''
+FIXME
+
+This script is used only to call gdbus-codegen and simulate the
+generation of the source code and header as different targets.
+
+Both are generated implicitly, so meson is not able to know how
+many files are generated, so it does generate only one opaque
+target that represents the two files.
+
+Please see:
+   https://bugzilla.gnome.org/show_bug.cgi?id=791015
+   https://github.com/mesonbuild/meson/pull/2930
+'''
+
+import subprocess
+import sys
+
+name = 'org.gnome.' + sys.argv[1]
+
+subprocess.call([
+  'gdbus-codegen',
+  '--interface-prefix=' + name + '.',
+  '--generate-c-code=' + sys.argv[2],
+  '--c-namespace=Gsd',
+  '--annotate', name, 'org.gtk.GDBus.C.Name', sys.argv[1],
+  '--output-directory=' + sys.argv[3],
+  sys.argv[4]
+])
diff --git a/gnome-settings-daemon/meson.build b/gnome-settings-daemon/meson.build
index 7039fa5..6c17900 100644
--- a/gnome-settings-daemon/meson.build
+++ b/gnome-settings-daemon/meson.build
@@ -9,15 +9,38 @@ dbus_ifaces = [
   ['Shell', 'gsd-shell-glue']
 ]
 
+dbus_headers = []
+
+codegen = find_program('codegen.py')
+
 foreach iface: dbus_ifaces
   name = 'org.gnome.' + iface[0]
-  sources += gnome.gdbus_codegen(
+
+  # FIXME: Opaque target return from gdbus_codegen
+  # Please see:
+  #   https://bugzilla.gnome.org/show_bug.cgi?id=791015
+  #   https://github.com/mesonbuild/meson/pull/2930
+  '''
+  dbus_sources += gnome.gdbus_codegen(
     iface[1],
     name + '.xml',
     interface_prefix: name + '.',
     namespace: 'Gsd',
     annotations: [name, 'org.gtk.GDBus.C.Name', iface[0]]
   )
+  '''
+
+  # FIXME: Ugly workaround that simulates the generation of
+  #        two different targets.
+  dbus_sources = custom_target(
+    iface[1],
+    input: name + '.xml',
+    output: [iface[1] + '.h', iface[1] + '.c'],
+    command: [codegen, iface[0], iface[1], meson.current_build_dir(), '@INPUT@', '@OUTPUT@']
+  )
+
+  dbus_headers += dbus_sources[0]
+  sources += dbus_sources[1]
 endforeach
 
 deps = [gio_unix_dep]
@@ -28,7 +51,7 @@ endif
 
 libgsd = shared_library(
   'gsd',
-  sources: sources,
+  sources: sources + dbus_headers,
   include_directories: top_inc,
   dependencies: deps,
   install: true,
@@ -36,6 +59,7 @@ libgsd = shared_library(
 )
 
 libgsd_dep = declare_dependency(
+  sources: dbus_headers,
   include_directories: include_directories('.'),
   link_with: libgsd
 )