Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 42511)
+++ /trunk/Config.kmk	(revision 42512)
@@ -2178,5 +2178,5 @@
 
 VBOX_GCC_CHECK_CXX = $(shell \
-   if $(TOOL_$(VBOX_GCC_TOOL)_CXX) $(1) -S -o /dev/null -xc++ /dev/null > /dev/null 2>&1; \
+   if $(TOOL_$(VBOX_GCC_TOOL)_CXX) $(subst -Wno-,-W,$(1)) -S -o /dev/null -xc++ /dev/null > /dev/null 2>&1; \
    then echo "$(1)"; \
    else echo "$(2)"; fi; )
@@ -2230,5 +2230,5 @@
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wlogical-op           ?= $(call VBOX_GCC_CHECK_CC,-Wlogical-op,)'
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-address           ?= $(call VBOX_GCC_CHECK_CXX,-Wno-address,)'
-	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-delete-non-virtual-dtor    ?= $(call VBOX_GCC_CHECK_CXX,-Wdelete-non-virtual-dtor,)'
+	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-delete-non-virtual-dtor    ?= $(call VBOX_GCC_CHECK_CXX,-Wno-delete-non-virtual-dtor,)'
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-int-to-pointer-cast        ?= $(call VBOX_GCC_CHECK_CC,-Wno-int-to-pointer-cast,)'
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-invalid-offsetof           ?= $(call VBOX_GCC_CHECK_CXX,-Wno-invalid-offsetof,)'