qt5base: make harfbuzz support selectable

If selected use:

 - system/buildroot harfbuzz in case __sync for 4 bytes is supported
 - qt harfbuzz otherwise (using QAtomic instead)

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/qt5/qt5base/Config.in

@@ -229,6 +229,14 @@ config BR2_PACKAGE_QT5BASE_FONTCONFIG
 	  This option enables Fontconfig and Freetype support using
 	  the system fontconfig and freetype2 libraries.
 
+config BR2_PACKAGE_QT5BASE_HARFBUZZ
+	bool "harfbuzz support"
+	select BR2_PACKAGE_HARFBUZZ if BR2_TOOLCHAIN_HAS_SYNC_4
+	help
+	  This option enables HarfBuzz support (either system harfbuzz
+	  if the toolchain supports __sync for 4 bytes, or the qt
+	  provided one which avoids this dependency by using QAtomic).
+
 config BR2_PACKAGE_QT5BASE_GIF
 	bool "GIF support"
 	help

package/qt5/qt5base/qt5base.mk

@@ -105,6 +105,22 @@ QT5BASE_DEPENDENCIES += freetype
 else
 QT5BASE_CONFIGURE_OPTS += -no-gui -no-freetype
 endif
+
+ifeq ($(BR2_PACKAGE_QT5BASE_HARFBUZZ),y)
+ifeq ($(BR2_TOOLCHAIN_HAS_SYNC_4),y)
+# system harfbuzz in case __sync for 4 bytes is supported
+QT5BASE_CONFIGURE_OPTS += -system-harfbuzz
+QT5BASE_DEPENDENCIES += harfbuzz
+else
+# qt harfbuzz otherwise (using QAtomic instead)
+QT5BASE_CONFIGURE_OPTS += -qt-harfbuzz
+QT5BASE_LICENSE := $(QT5BASE_LICENSE), MIT (harfbuzz)
+QT5BASE_LICENSE_FILES += src/3rdparty/harfbuzz-ng/COPYING
+endif
+else
+QT5BASE_CONFIGURE_OPTS += -no-harfbuzz
+endif
+
 QT5BASE_CONFIGURE_OPTS += $(if $(BR2_PACKAGE_QT5BASE_WIDGETS),-widgets,-no-widgets)
 # We have to use --enable-linuxfb, otherwise Qt thinks that -linuxfb
 # is to add a link against the "inuxfb" library.