[clutter-gtk] build: Include builddir in the gtk-doc DOC_SOURCE_DIR

[Emmanuele Bassi <ebassi src gnome org>]

commit 4c082e5e1666959ec394aff65870176c4b35e241
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Sep 15 13:30:16 2015 +0100

    build: Include builddir in the gtk-doc DOC_SOURCE_DIR
    
    Allows GTK-Doc to find some symbols during distcheck.

 doc/reference/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/doc/reference/Makefile.am b/doc/reference/Makefile.am
index 345e51d..8c28954 100644
--- a/doc/reference/Makefile.am
+++ b/doc/reference/Makefile.am
@@ -15,7 +15,7 @@ DOC_MAIN_SGML_FILE=$(DOC_MODULE)-docs.xml
 # gtk-doc will search all .c & .h files beneath here for inline comments
 # documenting the functions and macros.
 # e.g. DOC_SOURCE_DIR=../../../gtk
-DOC_SOURCE_DIR=../../clutter-gtk
+DOC_SOURCE_DIR=$(top_srcdir)/clutter-gtk $(top_builddir)/clutter-gtk
 
 # Extra options to pass to gtkdoc-scangobj. Not normally needed.
 SCANGOBJ_OPTIONS=--type-init-func="clutter_base_init()"