package/qt5tools: enable build of host qdoc

qdoc was previously built as part of qtbase (in the pre-5.6 era), but
with qt-5.6 it is now part of qttools.

With qt-5.12, it needs libclang to build, so be it...

Signed-off-by: Yann E. MORIN <yann.morin@orange.com>
Cc: Peter Seiderer <ps.report@gmx.net>
Cc: Julien Corjon <corjon.j@ecagroup.com>
Reviewed-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/qt5/qt5tools/Config.in

@@ -17,6 +17,16 @@ config BR2_PACKAGE_QT5TOOLS_LINGUIST_TOOLS
 	  This option enables the linguist host tools
 	  lconvert, lrelease and lupdate.
 
+config BR2_PACKAGE_QT5TOOLS_QDOC_TOOL
+	bool "qdoc host tool"
+	depends on !BR2_PACKAGE_QT5_VERSION_LATEST \
+		|| BR2_HOST_GCC_AT_LEAST_4_8 # host-clang
+	help
+	  This option enables the qdoc host tool.
+
+comment "qdoc host tool needs host gcc >= 4.8"
+	depends on BR2_PACKAGE_QT5_VERSION_LATEST && !BR2_HOST_GCC_AT_LEAST_4_8
+
 config BR2_PACKAGE_QT5TOOLS_PIXELTOOL
 	bool "pixeltool"
 	select BR2_PACKAGE_QT5BASE_GUI

package/qt5/qt5tools/qt5tools.mk

@@ -29,11 +29,13 @@ endif
 
 QT5TOOLS_BUILD_DIRS_$(BR2_PACKAGE_QT5TOOLS_LINGUIST_TOOLS) += \
 	linguist/lconvert linguist/lrelease linguist/lupdate
-ifeq ($(BR2_PACKAGE_QT5TOOLS_LINGUIST_TOOLS),y)
-# use install target to copy cmake module files
-define QT5TOOLS_INSTALL_STAGING_CMDS
-	$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/src/linguist install
-endef
+QT5TOOLS_INSTALL_STAGING_DIR_$(BR2_PACKAGE_QT5TOOLS_LINGUIST_TOOLS) += \
+	linguist
+
+ifeq ($(BR2_PACKAGE_QT5TOOLS_QDOC_TOOL),y)
+QT5TOOLS_BUILD_DIRS_y += qdoc
+QT5TOOLS_INSTALL_STAGING_DIR_y += qdoc
+QT5TOOLS_DEPENDENCIES += $(if $(BR2_PACKAGE_QT5_VERSION_LATEST),host-clang)
 endif
 
 QT5TOOLS_BUILD_DIRS_$(BR2_PACKAGE_QT5TOOLS_PIXELTOOL) += pixeltool
@@ -58,6 +60,12 @@ define QT5TOOLS_BUILD_CMDS
 		$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/src/$(p)$(sep))
 endef
 
+# use install target to copy cmake module files
+define QT5TOOLS_INSTALL_STAGING_CMDS
+	$(foreach p,$(QT5TOOLS_INSTALL_STAGING_DIR_y), \
+		$(TARGET_MAKE_ENV) $(MAKE) -C $(@D)/src/$(p) install$(sep))
+endef
+
 define QT5TOOLS_INSTALL_TARGET_CMDS
 	$(foreach p,$(QT5TOOLS_INSTALL_TARGET_y), \
 		$(INSTALL) -D -m0755 $(@D)/bin/$(p) $(TARGET_DIR)/usr/bin/$(p)$(sep))