build: Make abicheck.sh backend-aware

It should be possible to adapt the abicheck.sh script so that it
actually tests the ABI of libclutter-1.0.so taking into account
the backends that were compiled into Clutter, and avoid expected
failures if Clutter was not built with a specific backend.

https://bugzilla.gnome.org/show_bug.cgi?id=670680

clutter/Makefile.am

@@ -983,7 +983,7 @@ clutter_all_c_sources = \
 	$(cally_sources_c) \
 	$(built_source_c)
 
-TESTS_ENVIRONMENT = srcdir="$(srcdir)" clutter_all_c_sources="$(clutter_all_c_sources)"
+TESTS_ENVIRONMENT = srcdir="$(srcdir)" CLUTTER_BACKENDS="$(CLUTTER_BACKENDS)"
 if OS_LINUX
 TESTS = abicheck.sh
 endif

clutter/abicheck.sh

@@ -1,11 +1,24 @@
 #! /bin/sh
 
-cpp -P \
-        -DG_OS_UNIX \
-        -DCLUTTER_WINDOWING_X11 \
-        -DCLUTTER_WINDOWING_GLX \
-        -DCLUTTER_WINDOWING_GDK \
-        ${srcdir:-.}/clutter.symbols | sed -e '/^$/d' -e 's/ G_GNUC.*$//' -e 's/ PRIVATE//' -e 's/ DATA//' | sort > expected-abi
+has_x11_backend=no
+has_gdk_backend=no
+for backend in ${CLUTTER_BACKENDS}; do
+        case "$backend" in
+                x11) has_x11_backend=yes ;;
+                gdk) has_gdk_backend=yes ;;
+        esac
+done
+
+cppargs="-DG_OS_UNIX"
+if [ $has_x11_backend = "yes" ]; then
+        cppargs="$cppargs -DCLUTTER_WINDOWING_X11 -DCLUTTER_WINDOWING_GLX"
+fi
+
+if [ $has_gdk_backend = "yes" ]; then
+        cppargs="$cppargs -DCLUTTER_WINDOWING_GDK"
+fi
+
+cpp -P ${cppargs} ${srcdir:-.}/clutter.symbols | sed -e '/^$/d' -e 's/ G_GNUC.*$//' -e 's/ PRIVATE//' -e 's/ DATA//' | sort > expected-abi
 
 nm -D -g --defined-only .libs/libclutter-1.0.so | cut -d ' ' -f 3 | egrep -v '^(__bss_start|_edata|_end)' | sort > actual-abi
 diff -u expected-abi actual-abi && rm -f expected-abi actual-abi